{"title":"Sky-Watcher Esprit","description":"\u003cp\u003eThe Sky-Watcher Esprit line, listed by aperture. Part of \u003ca href=\"\/collections\/sky-watcher-telescopes\"\u003eSky-Watcher Telescopes\u003c\/a\u003e.\u003c\/p\u003e","products":[{"product_id":"skywatcher-esprit-80ed-apo-triplet","title":"Skywatcher Esprit 80ED APO Triplet","description":"\u003cdiv\u003e\u003cspan style=\"font-family: Arial;\"\u003eSkywatcher Esprit 80ED, 100ED, 120ED and 150ED Super APO refractors have a doublet field flattener to get a flat field and minimize aberration and distortion. Their wide 48mm opener ensures a larger and clearer aperture and also extremely minimized halation. Connect the triplet and doublet field flattener with a high precision thin thread to keep the optical axis perpendicular to the image. \u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan style=\"font-family: Arial;\"\u003e \u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\n\u003cp style=\"box-sizing: border-box;\"\u003eDesigned with the discerning astrophotographer in mind, Sky-Watcher USA’s top-of-the-line Esprit refractors deliver the kind of imaging performance one would expect from telescopes costing thousands of dollars more.\u003c\/p\u003e\n\u003cp style=\"box-sizing: border-box;\"\u003eWith their three-element air spaced objective lens design, false color is completely eliminated, yielding exceptional contrast and sharpness. The included 2-element field corrector guarantees a flat field across the entire imaging plane. The Sky-Watcher exclusive Helinear Track focusing system provides a smooth, rock-solid focuser with zero image shift.\u003c\/p\u003e\n\u003cp style=\"box-sizing: border-box;\"\u003eAll Sky-Watcher USA Esprit refractors come with a 8 x 50 right angle finderscope, 2-inch Star diagonal, 2-element field flattener*, camera adapter, D-style dovetail and padded case. Everything you need to get out under the stars.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan style=\"font-family: Arial;\"\u003e \u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan style=\"font-family: Arial;\"\u003eMain Features: \u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan style=\"font-family: Arial;\"\u003e- Premium optical materials \u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan style=\"font-family: Arial;\"\u003e- Short focal length and full frame corrected focal plane \u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan style=\"font-family: Arial;\"\u003e- Excellent field flatness \u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan style=\"font-family: Arial;\"\u003e- Precision linear power focuser is standard \u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan style=\"font-family: Arial;\"\u003e- Metallic high-transmission lens coatings \u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan style=\"font-family: Arial;\"\u003e- Light-baffled optical systems \u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan style=\"font-family: Arial;\"\u003e- Telescope tube attachment hardware \u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan style=\"font-family: Arial;\"\u003e- Zero detectable Colour Fringing even on Bright Objects\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan style=\"font-family: Arial;\"\u003e- Knife-edge Baffled Optical System\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e \u003c\/div\u003e\n\u003cdiv\u003e\u003cstrong\u003eThis is a final sale item.  Brand new with full manufacture warranty.\u003c\/strong\u003e\u003c\/div\u003e","brand":"Sky-Watcher","offers":[{"title":"Default Title","offer_id":44013469401199,"sku":"S11400","price":3200.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/en_telescope_caty01358550342__78737.jpg?v=1766554085"},{"product_id":"skywatcher-esprit-100ed-apo-triplet","title":"Skywatcher Esprit 100ED APO Triplet","description":"\u003cdiv\u003e\u003cspan style=\"font-family: Arial;\"\u003eSkywatcher Esprit 80ED, 100ED, 120ED and 150ED Super APO refractors have a doublet field flattener to get a flat field and minimize aberration and distortion. Their wide 48mm opener ensures a larger and clearer aperture and also extremely minimized halation. Connect the triplet and doublet field flattener with a high precision thin thread to keep the optical axis perpendicular to the image. \u003c\/span\u003e\u003c\/div\u003e\u003cdiv\u003e\u003cspan style=\"font-family: Arial;\"\u003e\u003cbr\u003e\u003c\/span\u003e\u003c\/div\u003e\u003cdiv\u003e\n\u003cp style=\"box-sizing: border-box; font-family: \" open sans arial sans-serif margin: font-size:\u003eDesigned with the discerning astrophotographer in mind, Sky-Watcher USA’s top-of-the-line Esprit refractors deliver the kind of imaging performance one would expect from telescopes costing thousands of dollars more.\u003c\/p\u003e\n\u003cp style=\"box-sizing: border-box; font-family: \" open sans arial sans-serif margin: font-size:\u003eWith their three-element air spaced objective lens design, false color is completely eliminated, yielding exceptional contrast and sharpness. The included 2-element field corrector guarantees a flat field across the entire imaging plane. The Sky-Watcher exclusive Helinear Track focusing system provides a smooth, rock-solid focuser with zero image shift.\u003c\/p\u003e\n\u003cp style=\"box-sizing: border-box; font-family: \" open sans arial sans-serif margin: font-size:\u003eAll Sky-Watcher USA Esprit refractors come with a 8 x 50 right angle finderscope, 2-inch Star diagonal, 2-element field flattener*, camera adapter, D-style dovetail and padded case. Everything you need to get out under the stars.\u003c\/p\u003e\n\u003c\/div\u003e\u003cdiv\u003e\u003cspan style=\"font-family: Arial;\"\u003e\u003cbr\u003e\u003c\/span\u003e\u003c\/div\u003e\u003cdiv\u003e\u003cspan style=\"font-family: Arial;\"\u003eMain Features: \u003c\/span\u003e\u003c\/div\u003e\u003cdiv\u003e\u003cspan style=\"font-family: Arial;\"\u003e- Premium optical materials \u003c\/span\u003e\u003c\/div\u003e\u003cdiv\u003e\u003cspan style=\"font-family: Arial;\"\u003e- Short focal length and full frame corrected focal plane \u003c\/span\u003e\u003c\/div\u003e\u003cdiv\u003e\u003cspan style=\"font-family: Arial;\"\u003e- Excellent field flatness \u003c\/span\u003e\u003c\/div\u003e\u003cdiv\u003e\u003cspan style=\"font-family: Arial;\"\u003e- Precision linear power focuser is standard \u003c\/span\u003e\u003c\/div\u003e\u003cdiv\u003e\u003cspan style=\"font-family: Arial;\"\u003e- Metallic high-transmission lens coatings \u003c\/span\u003e\u003c\/div\u003e\u003cdiv\u003e\u003cspan style=\"font-family: Arial;\"\u003e- Light-baffled optical systems \u003c\/span\u003e\u003c\/div\u003e\u003cdiv\u003e\u003cspan style=\"font-family: Arial;\"\u003e- Telescope tube attachment hardware \u003c\/span\u003e\u003c\/div\u003e\u003cdiv\u003e\u003cspan style=\"font-family: Arial;\"\u003e- Zero detectable Colour Fringing even on Bright Objects\u003c\/span\u003e\u003c\/div\u003e\u003cdiv\u003e\u003cspan style=\"font-family: Arial;\"\u003e- Knife-edge Baffled Optical System\u003c\/span\u003e\u003c\/div\u003e","brand":"Sky-Watcher","offers":[{"title":"Default Title","offer_id":44013469433967,"sku":"S11410","price":4460.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/esprit100-left-profile-600x600__26983.jpg?v=1766554093"},{"product_id":"skywatcher-esprit-120ed-apo-triplet","title":"Skywatcher Esprit 120ED APO Triplet","description":"\u003cdiv\u003e\u003cspan style=\"font-family: Arial;\"\u003eSkywatcher Esprit 80ED, 100ED, 120ED and 150ED Super APO refractors have a doublet field flattener to get a flat field and minimize aberration and distortion. Their wide 48mm opener ensures a larger and clearer aperture and also extremely minimized halation. Connect the triplet and doublet field flattener with a high precision thin thread to keep the optical axis perpendicular to the image. \u003c\/span\u003e\u003c\/div\u003e\u003cdiv\u003e\u003cspan style=\"font-family: Arial;\"\u003e\u003cbr\u003e\u003c\/span\u003e\u003c\/div\u003e\u003cdiv\u003e\n\u003cp style=\"box-sizing: border-box; font-family: \" open sans arial sans-serif margin: font-size:\u003eDesigned with the discerning astrophotographer in mind, Sky-Watcher USA’s top-of-the-line Esprit refractors deliver the kind of imaging performance one would expect from telescopes costing thousands of dollars more.\u003c\/p\u003e\n\u003cp style=\"box-sizing: border-box; font-family: \" open sans arial sans-serif margin: font-size:\u003eWith their three-element air spaced objective lens design, false color is completely eliminated, yielding exceptional contrast and sharpness. The included 2-element field corrector guarantees a flat field across the entire imaging plane. The Sky-Watcher exclusive Helinear Track focusing system provides a smooth, rock-solid focuser with zero image shift.\u003c\/p\u003e\n\u003cp style=\"box-sizing: border-box; font-family: \" open sans arial sans-serif margin: font-size:\u003eAll Sky-Watcher USA Esprit refractors come with a 8 x 50 right angle finderscope, 2-inch Star diagonal, 2-element field flattener*, camera adapter, D-style dovetail and padded case. Everything you need to get out under the stars.\u003c\/p\u003e\n\u003c\/div\u003e\u003cdiv\u003e\u003cspan style=\"font-family: Arial;\"\u003e\u003cbr\u003e\u003c\/span\u003e\u003c\/div\u003e\u003cdiv\u003e\u003cspan style=\"font-family: Arial;\"\u003eMain Features: \u003c\/span\u003e\u003c\/div\u003e\u003cdiv\u003e\u003cspan style=\"font-family: Arial;\"\u003e- Premium optical materials \u003c\/span\u003e\u003c\/div\u003e\u003cdiv\u003e\u003cspan style=\"font-family: Arial;\"\u003e- Short focal length and full frame corrected focal plane \u003c\/span\u003e\u003c\/div\u003e\u003cdiv\u003e\u003cspan style=\"font-family: Arial;\"\u003e- Excellent field flatness \u003c\/span\u003e\u003c\/div\u003e\u003cdiv\u003e\u003cspan style=\"font-family: Arial;\"\u003e- Precision linear power focuser is standard \u003c\/span\u003e\u003c\/div\u003e\u003cdiv\u003e\u003cspan style=\"font-family: Arial;\"\u003e- Metallic high-transmission lens coatings \u003c\/span\u003e\u003c\/div\u003e\u003cdiv\u003e\u003cspan style=\"font-family: Arial;\"\u003e- Light-baffled optical systems \u003c\/span\u003e\u003c\/div\u003e\u003cdiv\u003e\u003cspan style=\"font-family: Arial;\"\u003e- Telescope tube attachment hardware \u003c\/span\u003e\u003c\/div\u003e\u003cdiv\u003e\u003cspan style=\"font-family: Arial;\"\u003e- Zero detectable Colour Fringing even on Bright Objects\u003c\/span\u003e\u003c\/div\u003e\u003cdiv\u003e\u003cspan style=\"font-family: Arial;\"\u003e- Knife-edge Baffled Optical System\u003c\/span\u003e\u003c\/div\u003e","brand":"Sky-Watcher","offers":[{"title":"Default Title","offer_id":44013469466735,"sku":"S11420","price":5790.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/esprit120-front-left-600x600__96622.jpg?v=1766554100"},{"product_id":"skywatcher-esprit-150ed-apo-triplet","title":"Skywatcher Esprit 150ED APO Triplet","description":"\u003cdiv\u003e\u003cspan style=\"font-family: Arial;\"\u003eSkywatcher Esprit 80ED, 100ED, 120ED and 150ED Super APO refractors have a doublet field flattener to get a flat field and minimize aberration and distortion. Their wide 48mm opener ensures a larger and clearer aperture and also extremely minimized halation. Connect the triplet and doublet field flattener with a high precision thin thread to keep the optical axis perpendicular to the image. \u003c\/span\u003e\u003c\/div\u003e\u003cdiv\u003e\u003cspan style=\"font-family: Arial;\"\u003e\u003cbr\u003e\u003c\/span\u003e\u003c\/div\u003e\u003cdiv\u003e\n\u003cp style=\"box-sizing: border-box; font-family: \" open sans arial sans-serif margin: font-size:\u003eDesigned with the discerning astrophotographer in mind, Sky-Watcher USA’s top-of-the-line Esprit refractors deliver the kind of imaging performance one would expect from telescopes costing thousands of dollars more.\u003c\/p\u003e\n\u003cp style=\"box-sizing: border-box; font-family: \" open sans arial sans-serif margin: font-size:\u003eWith their three-element air spaced objective lens design, false color is completely eliminated, yielding exceptional contrast and sharpness. The included 2-element field corrector guarantees a flat field across the entire imaging plane. The Sky-Watcher exclusive Helinear Track focusing system provides a smooth, rock-solid focuser with zero image shift.\u003c\/p\u003e\n\u003cp style=\"box-sizing: border-box; font-family: \" open sans arial sans-serif margin: font-size:\u003eAll Sky-Watcher USA Esprit refractors come with a 8 x 50 right angle finderscope, 2-inch Star diagonal, 2-element field flattener*, camera adapter, D-style dovetail and padded case. Everything you need to get out under the stars.\u003c\/p\u003e\n\u003c\/div\u003e\u003cdiv\u003e\u003cspan style=\"font-family: Arial;\"\u003e\u003cbr\u003e\u003c\/span\u003e\u003c\/div\u003e\u003cdiv\u003e\u003cspan style=\"font-family: Arial;\"\u003eMain Features: \u003c\/span\u003e\u003c\/div\u003e\u003cdiv\u003e\u003cspan style=\"font-family: Arial;\"\u003e- Premium optical materials \u003c\/span\u003e\u003c\/div\u003e\u003cdiv\u003e\u003cspan style=\"font-family: Arial;\"\u003e- Short focal length and full frame corrected focal plane \u003c\/span\u003e\u003c\/div\u003e\u003cdiv\u003e\u003cspan style=\"font-family: Arial;\"\u003e- Excellent field flatness \u003c\/span\u003e\u003c\/div\u003e\u003cdiv\u003e\u003cspan style=\"font-family: Arial;\"\u003e- Precision linear power focuser is standard \u003c\/span\u003e\u003c\/div\u003e\u003cdiv\u003e\u003cspan style=\"font-family: Arial;\"\u003e- Metallic high-transmission lens coatings \u003c\/span\u003e\u003c\/div\u003e\u003cdiv\u003e\u003cspan style=\"font-family: Arial;\"\u003e- Light-baffled optical systems \u003c\/span\u003e\u003c\/div\u003e\u003cdiv\u003e\u003cspan style=\"font-family: Arial;\"\u003e- Telescope tube attachment hardware \u003c\/span\u003e\u003c\/div\u003e\u003cdiv\u003e\u003cspan style=\"font-family: Arial;\"\u003e- Zero detectable Colour Fringing even on Bright Objects\u003c\/span\u003e\u003c\/div\u003e\u003cdiv\u003e\u003cspan style=\"font-family: Arial;\"\u003e- Knife-edge Baffled Optical System\u003c\/span\u003e\u003c\/div\u003e","brand":"Sky-Watcher","offers":[{"title":"Default Title","offer_id":44013469499503,"sku":"S11430","price":11470.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/esprit150-front-left-600x600__13534.jpg?v=1766554109"},{"product_id":"esprit-100edx-super-apo-triplet","title":"Esprit 100EDX Super APO Triplet","description":"\u003cp class=\"MsoNormal\"\u003e\u003cb\u003eTHE ELITE ASTROGRAPHS FOR THE REST OF US\u003c\/b\u003e\u003c\/p\u003e\n\u003cp class=\"MsoNormal\"\u003eDesigned with the discerning astrophotographer in mind, Sky-Watcher’s ALL NEW top-of-the-line Esprit EDX refractors deliver the kind of imaging performance one would expect from telescopes costing thousands of dollars more. With the Esprit’s three-element, air-spaced objective lens design, false color is virtually eliminated, yielding exceptional contrast and sharpness. Each element is fully multi-coated with Sky-Watcher’s proprietary Metallic High-Transmission Coatings™ (MHTC)™, producing a transmission rate that rivals any refractor on the market.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eTriplet super-apochromatic design\u003c\/li\u003e\n\u003cli\u003eThree-element, air-spaced optical assembly virtually eliminates false color\u003c\/li\u003e\n\u003cli\u003e100mm aperture, 550mm focal length, f\/5.5 focal ratio\u003c\/li\u003e\n\u003cli\u003eFPL-53 glass\u003c\/li\u003e\n\u003cli\u003e3.4-inch linear rail rack-and-pinion with micro focus\u003c\/li\u003e\n\u003cli\u003eAluminum optical tube with white, glossy finish\u003c\/li\u003e\n\u003cli\u003eCamera Angle Adjuster and rotatable focuser\u003c\/li\u003e\n\u003cli\u003eSturdy carry handle attaches to tube rings\u003c\/li\u003e\n\u003cli\u003eIncluded accessories: Tube rings, D-style dovetail, M48 camera adapter, and padded hard case\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp class=\"MsoNormal\"\u003eIn addition to superb optics, all Esprits feature exclusive dual-speed, Helinear track focusers, which provide smooth, rock-solid focusing with zero image shift. Using a Camera Angle Adjuster which is found on the end of the focuser drawtube and allows for orientation of your camera or eyepieces without needing to rotate the entire focuser. The Esprit EDX 100, 120, and 150 also come stock with rotatable focusers.\u003c\/p\u003e\n\u003cp class=\"MsoNormal\"\u003eAll Sky-Watcher Esprit EDX refractors come with mounting rings, dovetail plate, camera adapter, and foam-lined hard case.\u003c\/p\u003e\n\u003cp class=\"MsoNormal\"\u003e\u003cb\u003eUnsurpassed Performance\u003c\/b\u003e\u003c\/p\u003e\n\u003cp class=\"MsoNormal\"\u003eEsprit EDXs use three-element air-spaced optics to deliver images equal to scopes costing thousands of dollars more.\u003c\/p\u003e\n\u003cp class=\"MsoNormal\"\u003e\u003cb\u003eAward-winning Optics\u003c\/b\u003e\u003c\/p\u003e\n\u003cp class=\"MsoNormal\"\u003eAll Sky-Watcher Esprit EDXs use laboratory matched lens assemblies, including extra-low dispersion elements, for unrivaled clarity and color correction.\u003c\/p\u003e\n\u003cp class=\"MsoNormal\"\u003e\u003cb\u003eExclusive Linear-track Focuser\u003c\/b\u003e\u003c\/p\u003e\n\u003cp class=\"MsoNormal\"\u003eSky-Watcher’s exclusive focuser design combines a rock-solid platform with zero image shift.\u003c\/p\u003e","brand":"Sky-Watcher","offers":[{"title":"Default Title","offer_id":52950752002159,"sku":"S11435","price":2910.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/Esprit100EDX_OTAOnly_LeftFront_1800x1800_130b76fb-a4f9-4bd3-abf5-42f0cd063316.webp?v=1776196420"},{"product_id":"sky-watcher-esprit-100edx-field-flattener","title":"Sky-Watcher Esprit 100EDX Field Flattener","description":"\u003ch3\u003e\u003cstrong\u003eProduct Overview\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eThe Esprit 100EDX Flattener is Sky-Watcher's dedicated field corrector for the Esprit 100EDX super apochromatic refractor. A fast triplet objective focuses onto a gently curved surface; a camera sensor is flat. The flattener resolves that mismatch, so stars hold their shape out to the frame edges instead of drawing short radial streaks in the corners while the centre of the frame stays sharp.\u003c\/p\u003e\n\u003cp\u003eSky-Watcher publishes a 44 mm corrected image circle for this corrector. That encloses the 43.3 mm diagonal of a full-frame sensor and covers APS-C with margin to spare, so framing choices are driven by focal length rather than by how much of the sensor the corrector reaches. On the Esprit 100EDX — published by Sky-Watcher as 100 mm aperture, 550 mm focal length, f\/5.5, FPL-53 triplet — that is a wide, fast field with corners that hold up.\u003c\/p\u003e\n\u003cp\u003eOne name to keep straight: this part is published for the \u003cstrong\u003eEsprit\u003c\/strong\u003e 100EDX, the super-apochromatic triplet. The \u003cstrong\u003eEvostar\u003c\/strong\u003e 100EDX doublet is served by a different corrector (S20216, which also covers the Esprit 70EDX).\u003c\/p\u003e\n\n\u003ch3\u003e\u003cstrong\u003eWho It's For\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eThis is the corrector Sky-Watcher pairs with the Esprit 100EDX, and it is the right part if you own that telescope and want flat, round stars across a large sensor at the scope's native focal length and ratio.\u003c\/p\u003e\n\u003cp\u003eIt suits deep-sky imagers working at the 100EDX's native 550 mm — large nebulae, open clusters, mid-size galaxy fields and mosaic panels — where the goal is a clean frame edge to edge rather than a shorter, faster field from a reducing corrector.\u003c\/p\u003e\n\n\u003ch3\u003e\u003cstrong\u003eKey Features \u0026amp; Design\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eMatched to the Esprit 100EDX:\u003c\/strong\u003e Sky-Watcher publishes compatibility with the Esprit 100EDX specifically. The correction is computed for that objective rather than sold as a universal flattener.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e44 mm corrected image circle:\u003c\/strong\u003e the published figure covers a full-frame sensor's 43.3 mm diagonal and leaves APS-C well inside the corrected zone.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFlattening only:\u003c\/strong\u003e Sky-Watcher publishes no reduction factor for this corrector, so the telescope's native 550 mm and f\/5.5 carry through it.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSingle-piece corrector:\u003c\/strong\u003e one optic in the imaging train between focuser and camera, with no separate elements to align.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003e\u003cstrong\u003eOptical \/ Mechanical Design\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003e\u003cstrong\u003eWhat it corrects:\u003c\/strong\u003e field curvature across the imaging field of the Esprit 100EDX. The visible symptom it removes is corner stars that elongate radially, pointing away from the frame centre, while the middle of the frame focuses cleanly.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eCorrected image circle:\u003c\/strong\u003e 44 mm, as published by Sky-Watcher. Sensor coverage follows directly from that number — a full-frame sensor measures 43.3 mm corner to corner and an APS-C sensor roughly 28 mm, so both sit inside the corrected field.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eResulting focal length and focal ratio:\u003c\/strong\u003e Sky-Watcher publishes no reduction factor and no altered figures, consistent with a flattener that works at native focal length. The Esprit 100EDX's published 550 mm and f\/5.5 are what you image at with this part in the train. At 550 mm across a 44 mm circle, a full-frame sensor takes in roughly three and a half degrees on the long axis, which is why this pairing suits large targets and mosaic work.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eRequired backfocus and thread interface:\u003c\/strong\u003e Sky-Watcher does not publish a backfocus distance in millimetres or a thread size for this corrector on its product page, and no manual or datasheet is linked there. Those two numbers determine how the corrector spaces to your sensor, and corner star shape is what depends on getting the spacing right. Send us your camera, filter drawer or filter wheel and any adapters and we will lay the train out with you before you order.\u003c\/p\u003e\n\n\u003ch3\u003e\u003cstrong\u003eRecommended Uses\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eDeep-sky astrophotography at native focal length:\u003c\/strong\u003e large emission nebulae, open clusters, mid-size galaxy fields and star fields at 550 mm.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eLarge-sensor imaging:\u003c\/strong\u003e the 44 mm circle supports full-frame and APS-C cameras, including cooled astronomical CMOS bodies in those formats.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMosaic panels:\u003c\/strong\u003e flat corners let adjacent panels blend without a ring of distorted stars at every seam.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eNarrowband and broadband alike:\u003c\/strong\u003e field curvature is a geometric error, so the correction applies regardless of the filter in front of the sensor.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003e\u003cstrong\u003eCompatibility and Accessory Notes\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eSky-Watcher lists one compatible telescope: the Esprit 100EDX. Their EDX correctors are published tube by tube — S20216 covers the Esprit 70EDX and the Evostar 100EDX, S20218 the Esprit 120EDX, S20219 the Esprit 150EDX — and refractors from other makers pair with their own. Tell us the exact model printed on your tube and we will confirm which corrector belongs on it.\u003c\/p\u003e\n\u003cp\u003eThe vendor does not publish the thread interface or the spacing distance to the sensor, so the adapters between this corrector and your camera cannot be specified from published data. Send us your camera model, filter wheel or drawer, and any off-axis guider in the train, and we will map the imaging train and tell you exactly what sits between the two.\u003c\/p\u003e\n\u003cp\u003eNothing about this part changes the mount side of the setup: it adds a short optic and roughly a pound behind the focuser rather than changing how the telescope mounts.\u003c\/p\u003e\n\n\u003ch3\u003e\u003cstrong\u003eGood to Know Before You Order\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eBackfocus is not published.\u003c\/strong\u003e Sky-Watcher gives no spacing figure in millimetres for this corrector. Corner star shape depends on hitting the correct sensor distance, and we can work that out with you from your specific camera and adapters.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eThread interface is not published.\u003c\/strong\u003e No thread size appears on the vendor page, so the camera-side connection is confirmed case by case rather than assumed.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eEsprit 100EDX, not Evostar 100EDX.\u003c\/strong\u003e The two share a 100 mm aperture and a similar name but take different correctors; the Evostar doublet is covered by S20216.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eIt is a flattener, not a reducer.\u003c\/strong\u003e No reduction factor is published, so focal length and focal ratio stay at the telescope's native values.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eBox contents are not published.\u003c\/strong\u003e The vendor states no spacer, adapter or case as supplied with the corrector.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWeight figure is the vendor's shipping weight.\u003c\/strong\u003e Sky-Watcher lists 1.0 lb for this item and publishes no separate optic-only mass in a specification table.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eVendor image note.\u003c\/strong\u003e Sky-Watcher states \"Images subject to change\" on this listing, which is normal for a recently released part.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003e\u003cstrong\u003eFrequently Asked Questions\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003e\u003cstrong\u003eIs it difficult to set up?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003ePhysically it is one optic that goes into the imaging train between the focuser and the camera, and it stays there. The part that takes attention is the spacing to the sensor, which Sky-Watcher does not publish for this corrector. Send us the camera and adapters you plan to use and we will lay out the train for you.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eDoes it change the focal length or focal ratio?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eSky-Watcher publishes no reduction factor, resulting focal length, or resulting focal ratio for this corrector. It flattens the field at the telescope's native 550 mm and f\/5.5.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWill it cover my full-frame camera?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eThe published corrected image circle is 44 mm and a full-frame sensor measures 43.3 mm across the diagonal, so the sensor sits inside the corrected field. APS-C sits well inside it.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eI have an Evostar 100EDX — is this the one?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eNo. The Evostar 100EDX doublet is published against S20216, the corrector shared with the Esprit 70EDX. This part is published for the Esprit 100EDX triplet. Send us the model printed on your tube and we will match it.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eDoes it fit the earlier Esprit 100ED?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eSky-Watcher publishes compatibility only with the Esprit 100EDX for this part. Earlier Esprit models have their own correctors in the range. Send us the model on your tube and we will confirm which one applies.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWhat weight does it add to the imaging train?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eSky-Watcher lists 1.0 lb for this item. It is a small addition behind the focuser next to the camera, filters and any guider.\u003c\/p\u003e\n\n\u003ch3\u003e\u003cstrong\u003eBottom Line\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eA dedicated flattener for the Esprit 100EDX with a published 44 mm corrected circle — enough to keep stars round across a full-frame sensor at the telescope's native 550 mm and f\/5.5. Sky-Watcher leaves the backfocus and thread figures unpublished, so we confirm the spacing with you against your own camera and adapters and send it out ready to drop into the train.\u003c\/p\u003e","brand":"Sky-Watcher","offers":[{"title":"Default Title","offer_id":53896756691055,"sku":"S20217","price":330.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/100_2.jpg?v=1785253569"},{"product_id":"sky-watcher-esprit-70edx-super-apo-triplet-refractor","title":"Sky-Watcher Esprit 70EDX Super APO Triplet Refractor","description":"\u003ch3\u003e\u003cstrong\u003eProduct Overview\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eThe Esprit 70EDX is a 70 mm f\/6.5 air-spaced triplet apochromat built around imaging. Its 455 mm focal length frames the large emission nebulae, open clusters and comet tails that overflow a longer scope, and the three-element objective uses FCD-100 extra-low dispersion glass, fully multi-coated with Sky-Watcher's Metallic High-Transmission Coatings (MHTC), to hold colour correction across that wide field. The optical tube weighs 3.3 kg (7.3 lbs) and measures 35 cm (13.8 in) with the dew shield threaded on, which puts it well inside the payload of a small equatorial or strain-wave mount even after a camera, filter wheel and guider are hanging off the back.\u003c\/p\u003e\n\u003cp\u003eIt ships with tube rings, a V-style dovetail, an M48 camera adapter and a padded hard case, so the tube arrives ready to bolt onto a mount and connect to a camera.\u003c\/p\u003e\n\n\u003ch3\u003e\u003cstrong\u003eWho It's For\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eThis is a good match if you shoot wide-field deep-sky targets and want stars that stay clean into the corners without a five-figure optic. It suits anyone building a travel or second imaging rig, anyone whose mount is small enough that a 3.3 kg tube is the difference between comfortable and marginal, and anyone moving from a doublet who has run out of patience with violet halos on bright stars. It is equally at home as a wide-field visual refractor at low power.\u003c\/p\u003e\n\n\u003ch3\u003e\u003cstrong\u003eKey Features \u0026amp; Design\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eAir-spaced triplet apochromat:\u003c\/strong\u003e three elements including FCD-100 extra-low dispersion glass. The third element is what removes the residual violet bloom a doublet leaves on Vega, Rigel and bright planetary detail.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMetallic High-Transmission Coatings (MHTC):\u003c\/strong\u003e every element is fully multi-coated, so the extra air-glass surfaces of a triplet do not cost you throughput.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e2.7-inch dual-speed linear-track focuser:\u003c\/strong\u003e a CNC-machined 1:11 dual-speed rack-and-pinion running on a linear rail. The rail is what keeps a loaded imaging train from sagging as focus moves, and it is why the tube holds focus position with zero image shift.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCamera Angle Adjuster:\u003c\/strong\u003e located at the end of the focuser drawtube, it rotates the camera or eyepiece to frame a target without turning the whole focuser body or disturbing focus.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eThread-on dew shield:\u003c\/strong\u003e threads to the front cell rather than sliding, so it stays put and the tube packs down to 35 cm for transport.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCarry handle:\u003c\/strong\u003e attaches to the tube rings for one-handed moves between the car and the mount.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eIncluded:\u003c\/strong\u003e tube rings, V-style dovetail, M48 camera adapter and a padded hard case.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003e\u003cstrong\u003eOptical \/ Mechanical Design\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eThe objective is an air-spaced triplet: three separately mounted elements with air gaps rather than a cemented stack. Air spacing lets Sky-Watcher figure each surface independently and gives the design the freedom to bring red, green and blue to a common focus. With FCD-100 as the low-dispersion element, the colour error that would otherwise show as a violet ring on the brightest stars falls below what a typical pixel scale resolves.\u003c\/p\u003e\n\u003cp\u003eMechanically the tube is aluminium with a white gloss finish. The focuser is the part that matters most for imaging: at 2.7 inches with an 11:1 fine control, it carries a full imaging train without flexure, and the linear rail means the drawtube travels straight instead of tipping under load. Visual back focus is greater than 160 mm (6.3 in), which leaves room for a diagonal and long eyepieces as well as a deep camera stack.\u003c\/p\u003e\n\n\u003ch3\u003e\u003cstrong\u003eRecommended Uses\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eWide-field deep-sky imaging:\u003c\/strong\u003e 455 mm at f\/6.5 covers North America Nebula, the Veil, M31, the Pleiades and the larger Sharpless regions on a single frame.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eNarrowband from light-polluted skies:\u003c\/strong\u003e f\/6.5 is fast enough that long narrowband subs stay practical.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTravel and grab-and-go imaging:\u003c\/strong\u003e 3.3 kg and 35 cm packed, in a hard case.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eRich-field visual observing:\u003c\/strong\u003e low-power sweeping through the Milky Way, large clusters and comets.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eGuide or companion scope:\u003c\/strong\u003e riding alongside a longer instrument on a mount with capacity to spare.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003e\u003cstrong\u003eCompatibility and Accessory Notes\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eSky-Watcher publishes a fully illuminated field of 30 mm (1.18 in) with the matching two-element thread-on field flattener. A 30 mm circle covers APS-C, whose diagonal is about 28 mm, with a little to spare; a full-frame sensor at 43 mm diagonal will show fall-off in the corners. The flattener is what turns a fast triplet into a flat-field astrograph, and the spacing it needs is specific: 100.06 mm (2.6 in) from the flattener to the sensor. Corner star shape follows directly from hitting that number.\u003c\/p\u003e\n\u003cp\u003eThe thread interfaces are M65 x 1 at the focuser drawtube, M62 x 1 at the field flattener, and M48 x 0.75 at the flattener exit. The supplied M48 camera adapter connects a camera directly to the drawtube.\u003c\/p\u003e\n\u003cp\u003eThe V-style (Vixen) dovetail fits any standard Vixen saddle, which covers most small equatorial and strain-wave mounts. These figures are published for the Esprit 70EDX; the other Esprit EDX sizes pair with their own correctors. Send us your camera, filter wheel and spacer stack and we will work the 100.06 mm out with you before you order.\u003c\/p\u003e\n\n\u003ch3\u003e\u003cstrong\u003eGood to Know Before You Order\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eThe field flattener is a separate purchase.\u003c\/strong\u003e The tube images without it, but flat corners across the 30 mm circle come from the matched two-element thread-on flattener. We stock it and can bundle the spacing.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eNo mount is included.\u003c\/strong\u003e This is an optical tube with rings and a dovetail. At 3.3 kg it is one of the easier triplets to mount, and a small equatorial or strain-wave head handles it with a camera attached.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eThe rotatable focuser is not part of this size.\u003c\/strong\u003e Sky-Watcher fits rotatable focusers to the Esprit EDX 100, 120 and 150. The 70EDX uses the Camera Angle Adjuster at the drawtube instead, which achieves camera rotation by a different route.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTwo weights are published.\u003c\/strong\u003e The optical tube itself is 3.3 kg (7.3 lbs); the shipping figure of 23.5 lb covers the tube, rings, dovetail, adapter and the foam-lined hard case together.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eVendor listings of the box contents differ slightly.\u003c\/strong\u003e The product page lists tube rings, V-style dovetail, M48 camera adapter and padded hard case; the manual's accessory line also mentions a 2-inch star diagonal. We confirm the exact contents of the carton before it leaves us.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003e\u003cstrong\u003eFrequently Asked Questions\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003e\u003cstrong\u003eIs it difficult to set up?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eNo. The tube arrives in its rings with the dovetail fitted, so the physical setup is dropping it into a saddle and tightening one clamp. The part that takes thought is the imaging train: the camera threads to the M48 adapter, and if you add the flattener the sensor sits 100.06 mm behind it. Once you have measured that stack once, it does not change.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWill it cover my camera?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eThe published illuminated field with the flattener is 30 mm, so APS-C and every smaller format are covered. Full frame extends past that circle and shows corner fall-off. Tell us which camera you are using and we will tell you what the corners will look like.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWhat mount does it need?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eAnything with a Vixen saddle and headroom past roughly 3.3 kg plus your camera. Small strain-wave heads and compact equatorials are the usual pairing, and the low weight is what keeps guiding easy.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eIs it usable for visual observing?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eYes. Visual back focus is greater than 160 mm, which accommodates a 2-inch diagonal and eyepieces. At 455 mm it is a wide-field instrument rather than a high-power planetary scope.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eHow does it differ from an ED doublet of the same aperture?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eThe third element. A doublet brings two wavelengths to common focus; the triplet brings three, which is what removes the violet halo around bright stars in long exposures.\u003c\/p\u003e\n\n\u003ch3\u003e\u003cstrong\u003eBottom Line\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eA 70 mm f\/6.5 FCD-100 triplet with a linear-track dual-speed focuser, a 30 mm illuminated field with its matched flattener, and a 3.3 kg tube that almost any mount can carry. It is the Esprit optical and mechanical package in the size that travels.\u003c\/p\u003e","brand":"Sky-Watcher","offers":[{"title":"Default Title","offer_id":53896760623215,"sku":"S11425","price":1800.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/Esprit70EDX_OTAOnly_FrontLeft.jpg?v=1785253637"},{"product_id":"sky-watcher-esprit-120edx-field-flattener","title":"Sky-Watcher Esprit 120EDX Field Flattener","description":"\u003ch3\u003e\u003cstrong\u003eProduct Overview\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eThe Esprit 120EDX Flattener is Sky-Watcher's dedicated field corrector for the Esprit 120EDX super apochromatic refractor. A fast triplet objective focuses onto a gently curved surface; a camera sensor is flat. The flattener resolves that mismatch so stars hold their shape out to the frame edges instead of drawing short radial streaks in the corners while the centre stays sharp.\u003c\/p\u003e\n\u003cp\u003eSky-Watcher publishes a 44 mm corrected image circle for this corrector. That encloses the 43.3 mm diagonal of a full-frame sensor and covers APS-C with margin to spare, so framing choices are driven by focal length rather than by how much of the sensor the corrector reaches.\u003c\/p\u003e\n\u003cp\u003eThis is a flattener, not a reducer. Sky-Watcher publishes no reduction factor and no altered focal length or focal ratio for it, so the Esprit 120EDX images at its native figures with this part in the train. The 0.77x Reducer\/Flattener for the Esprit 120 (S20209) is a separate optic with a different prescription.\u003c\/p\u003e\n\n\u003ch3\u003e\u003cstrong\u003eWho It's For\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eThis is the corrector Sky-Watcher pairs with the Esprit 120EDX, and it is the right part if you own that telescope and want flat, round stars across a large sensor at the scope's native focal length \u0026amp; ratio.\u003c\/p\u003e\n\u003cp\u003eIt suits deep-sky imagers who want the full native image scale — galaxies, globular clusters, planetary nebulae, small to mid-size emission targets — rather than the wider, faster field a reducing corrector produces. If your priority is shorter exposures and a wider frame, the 0.77x reducer\/flattener for the Esprit line is the part built for that job.\u003c\/p\u003e\n\n\u003ch3\u003e\u003cstrong\u003eKey Features \u0026amp; Design\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eMatched to the Esprit 120EDX:\u003c\/strong\u003e Sky-Watcher publishes compatibility with the Esprit 120EDX specifically. The correction is computed for that objective rather than sold as a universal flattener.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e44 mm corrected image circle:\u003c\/strong\u003e the published figure covers a full-frame sensor's 43.3 mm diagonal and leaves APS-C well inside the corrected zone.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFlattening only:\u003c\/strong\u003e no published reduction factor, so the telescope's native focal length and focal ratio carry through the corrector.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSingle-piece corrector:\u003c\/strong\u003e one optic in the imaging train between focuser and camera, with no separate elements to align.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003e\u003cstrong\u003eOptical \/ Mechanical Design\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003e\u003cstrong\u003eWhat it corrects:\u003c\/strong\u003e field curvature across the imaging field of the Esprit 120EDX. The visible symptom it removes is corner stars that elongate radially, pointing away from the frame centre, while the middle of the frame focuses cleanly.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eCorrected image circle:\u003c\/strong\u003e 44 mm, as published by Sky-Watcher. Sensor coverage follows directly from that number — a full-frame sensor measures 43.3 mm corner to corner and an APS-C sensor roughly 28 mm, so both sit inside the corrected field.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eResulting focal length and focal ratio:\u003c\/strong\u003e Sky-Watcher publishes none, consistent with a flattener that works at native focal length. We publish only what they publish, so no altered figures appear here.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eRequired backfocus and thread interface:\u003c\/strong\u003e Sky-Watcher does not publish a backfocus distance in millimetres or a thread size for this corrector on its product page, and no manual or datasheet is linked there. Those two numbers determine how the corrector spaces to your camera, so send us your camera, filter drawer and any adapters and we will work the train out with you before you order.\u003c\/p\u003e\n\n\u003ch3\u003e\u003cstrong\u003eRecommended Uses\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eDeep-sky astrophotography at native focal length:\u003c\/strong\u003e galaxies, globular clusters, planetary nebulae and compact emission regions where image scale matters more than field width.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eLarge-sensor imaging:\u003c\/strong\u003e the 44 mm circle supports full-frame and APS-C cameras, including cooled astronomical CMOS bodies in those formats.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMosaic panels:\u003c\/strong\u003e flat corners let adjacent panels blend without a ring of distorted stars at every seam.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eNarrowband and broadband alike:\u003c\/strong\u003e field curvature is a geometric error, so the correction applies regardless of the filter in front of the sensor.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003e\u003cstrong\u003eCompatibility and Accessory Notes\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eSky-Watcher lists one compatible telescope: the Esprit 120EDX. Other Esprit models — including the earlier Esprit 120ED — have their own correctors in Sky-Watcher's range, and refractors from other makers pair with their own. Tell us the exact model on your tube and we will confirm which corrector belongs on it.\u003c\/p\u003e\n\u003cp\u003eThe vendor does not publish the thread interface or the spacing distance to the sensor, so the adapters between this corrector and your camera cannot be specified from published data. Send us your camera model, filter wheel or drawer, and any off-axis guider in the train, and we will map the imaging train and tell you exactly what sits between the two.\u003c\/p\u003e\n\u003cp\u003eNothing about this part changes the mount side of the setup: it adds a short optic and roughly a pound behind the focuser rather than changing how the telescope mounts.\u003c\/p\u003e\n\n\u003ch3\u003e\u003cstrong\u003eGood to Know Before You Order\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eBackfocus is not published.\u003c\/strong\u003e Sky-Watcher gives no spacing figure in millimetres for this corrector. Corner star shape depends on hitting the correct sensor distance, and we can work that out with you from your specific camera and adapters.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eThread interface is not published.\u003c\/strong\u003e No thread size appears on the vendor page, so the camera-side connection is confirmed case by case rather than assumed.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePublished for the Esprit 120EDX.\u003c\/strong\u003e The 44 mm figure is stated for that telescope and is not carried across to other models.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eIt is a flattener, not a reducer.\u003c\/strong\u003e Focal length and focal ratio stay at the telescope's native values; the separate 0.77x reducer\/flattener is the part that changes them.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWeight figure is the vendor's shipping weight.\u003c\/strong\u003e Sky-Watcher lists 1.0 lb for this item and publishes no separate optic-only mass in a specification table.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eVendor image note.\u003c\/strong\u003e Sky-Watcher states \"Images subject to change\" on this listing, which is normal for a recently released part.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003e\u003cstrong\u003eFrequently Asked Questions\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003e\u003cstrong\u003eIs it difficult to set up?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003ePhysically it is one optic that goes into the imaging train between the focuser and the camera, and it stays there. The part that takes attention is the spacing to the sensor, which Sky-Watcher does not publish for this corrector. Send us the camera and adapters you plan to use and we will lay out the train for you.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eDoes it change the focal length or focal ratio?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eSky-Watcher publishes no reduction factor, resulting focal length, or resulting focal ratio for this corrector. It flattens the field at the telescope's native figures. The 0.77x Reducer\/Flattener is the part that shortens focal length and speeds the ratio.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWill it cover my full-frame camera?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eThe published corrected image circle is 44 mm and a full-frame sensor measures 43.3 mm across the diagonal, so the sensor sits inside the corrected field. APS-C sits well inside it.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eDoes it fit the Esprit 120ED rather than the 120EDX?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eSky-Watcher publishes compatibility only with the Esprit 120EDX for this part. The Esprit 120ED has its own correctors in the range, including a 0.77x reducer\/flattener. Send us the model printed on your tube and we will match it.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWhat weight does it add to the imaging train?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eSky-Watcher lists 1.0 lb for this item. It is a small addition behind the focuser next to the camera, filters and any guider.\u003c\/p\u003e\n\n\u003ch3\u003e\u003cstrong\u003eBottom Line\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eA dedicated flattener for the Esprit 120EDX with a published 44 mm corrected circle — enough to keep stars round across a full-frame sensor at the telescope's native focal length. Sky-Watcher leaves the backfocus and thread figures unpublished, so we confirm the spacing with you against your own camera and adapters and send it out ready to drop into the train.\u003c\/p\u003e","brand":"Sky-Watcher","offers":[{"title":"Default Title","offer_id":53896761639023,"sku":"S20218","price":440.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/120FieldCorrector_2_5fc66d00-f553-4b84-8181-6c6d16fc7c32.jpg?v=1785253650"},{"product_id":"sky-watcher-esprit-120edx-super-apo-triplet-refractor","title":"Sky-Watcher Esprit 120EDX Super APO Triplet Refractor","description":"\u003ch3\u003e\u003cstrong\u003eProduct Overview\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eThe Esprit 120EDX is a 120 mm f\/7 air-spaced triplet apochromat, the size in the Esprit EDX line where aperture and focal length start delivering resolution rather than just field. At 840 mm it is long enough for galaxies, globulars and planetary nebulae while still holding a usable field on a large sensor, and it resolves to 1.16 arc seconds by the Rayleigh criterion. The objective uses FPL-53 extra-low dispersion glass in a three-element air-spaced cell, fully multi-coated with Sky-Watcher's Metallic High-Transmission Coatings (MHTC), and gathers 294 times the light of the unaided eye.\u003c\/p\u003e\n\u003cp\u003eThe tube weighs 10.7 kg (25 lbs) and measures 70 cm (28 in) with the dew shield retracted. It ships with tube rings, a D-style dovetail, an accessory rail, an M48 camera adapter and a padded hard case.\u003c\/p\u003e\n\n\u003ch3\u003e\u003cstrong\u003eWho It's For\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eThis is a good match if you have a mount with real capacity and want a single refractor that images galaxies and shoots high-resolution lunar and planetary work without changing instruments. It suits imagers running full-frame or large APS-C sensors, observers who want a 120 mm apochromat for double stars and planets at 283x, and anyone stepping up from a 70 mm to 100 mm class refractor who has hit the resolution ceiling of the smaller aperture. At 10.7 kg it is a permanent-pier or heavy-portable instrument rather than a grab-and-go one.\u003c\/p\u003e\n\n\u003ch3\u003e\u003cstrong\u003eKey Features \u0026amp; Design\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eAir-spaced FPL-53 triplet:\u003c\/strong\u003e three elements with air gaps, built around FPL-53 extra-low dispersion glass. This is the glass type that lets a 120 mm f\/7 stay apochromatic rather than needing to be slowed down to control colour.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMetallic High-Transmission Coatings (MHTC):\u003c\/strong\u003e fully multi-coated throughout, so the six air-glass surfaces of the triplet do not eat into the light the 120 mm aperture collects.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eRotatable dual-speed focuser:\u003c\/strong\u003e a double-speed rack-and-pinion of 74 mm (3 in) diameter running on a linear rail. The 120EDX is one of the sizes that comes with a rotatable focuser as standard, in addition to the Camera Angle Adjuster.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCamera Angle Adjuster:\u003c\/strong\u003e at the end of the drawtube, it orients a camera or eyepiece without rotating the focuser body.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eRetractable dew shield:\u003c\/strong\u003e slides back over the tube, which is what keeps the packed length at 70 cm on a scope with an 840 mm focal length.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDeep back focus:\u003c\/strong\u003e greater than 225 mm (8.7 in) visually, which leaves room for long diagonals, binoviewers and deep camera trains.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eIncluded:\u003c\/strong\u003e tube rings, D-style dovetail, accessory rail, M48 camera adapter and a padded hard case.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003e\u003cstrong\u003eOptical \/ Mechanical Design\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eThe three elements sit in an air-spaced cell rather than a cemented doublet-plus-corrector stack. Each surface is figured independently, and the FPL-53 element carries the dispersion correction that brings red, green and blue to a common focus. The published performance follows from the aperture: 1.16 arc second Rayleigh resolution, 0.97 arc second by the Dawes limit, a limiting stellar magnitude of 12.9, and 294x the light-gathering power of the human eye. Useful magnification runs from 17x at the low end to 283x at the top.\u003c\/p\u003e\n\u003cp\u003eMechanically, the 74 mm rack-and-pinion focuser is sized for the load a 120 mm astrograph attracts. Its linear rail keeps the drawtube travelling straight under a full imaging train, and the dual-speed fine control is what makes focusing at f\/7 repeatable. The output thread is M74 x 1 with 6 mm of screw depth. The tube is aluminium with a white gloss finish, and the retractable dew cap shortens it for transport.\u003c\/p\u003e\n\n\u003ch3\u003e\u003cstrong\u003eRecommended Uses\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eDeep-sky astrophotography:\u003c\/strong\u003e 840 mm at f\/7 frames galaxies, globular clusters, planetary nebulae and the compact end of the emission-nebula catalogue.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFull-frame imaging with the matched flattener:\u003c\/strong\u003e the corrector covers a 44 mm imaging plane.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWider fields with the reducer-flattener:\u003c\/strong\u003e a shorter effective focal length over a 34 mm circle.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eHigh-resolution visual observing:\u003c\/strong\u003e double stars, lunar detail and planets at up to 283x with 1.16 arc second resolution.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eBinoviewing:\u003c\/strong\u003e back focus greater than 225 mm accommodates the light path a binoviewer adds.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003e\u003cstrong\u003eCompatibility and Accessory Notes\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eTwo correctors are published for this tube, each with its own spacing and its own covered circle. With the field flattener, the sensor sits exactly 75 mm behind the back of the flattener and full illumination extends across a 44 mm imaging plane, which covers full frame. With the reducer-flattener, the sensor sits exactly 95 mm behind the last lens and full illumination extends across 34 mm, which covers APS-C comfortably. Corner star shape depends on landing on those distances; for a CCD or a camera with an unusual back-focus depth, Sky-Watcher specifies a custom ring rather than a stack of generic spacers.\u003c\/p\u003e\n\u003cp\u003eThread interfaces are M74 x 1 at the focuser output, M62 x 1 female at the field flattener, and an M78 x 1 thread securing the ring at the reducer-flattener exit. The supplied M48 camera adapter connects a camera to the drawtube directly.\u003c\/p\u003e\n\u003cp\u003eThe D-style (Losmandy) dovetail fits any Losmandy-format saddle, which is what a 10.7 kg tube generally wants. These figures are published for the Esprit 120EDX; the other Esprit EDX sizes pair with their own correctors. Send us your camera, filter wheel and spacer list and we will work the 75 mm or 95 mm out with you before you order.\u003c\/p\u003e\n\n\u003ch3\u003e\u003cstrong\u003eGood to Know Before You Order\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eThe flattener and the reducer-flattener are separate purchases.\u003c\/strong\u003e Sky-Watcher states they are designed specifically for the Esprit 120 and must be bought separately. We stock the matching corrector and can supply it spaced.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eNo mount is included.\u003c\/strong\u003e The tube alone is 10.7 kg (25 lbs), and a camera, filter wheel and guider add to that. It is worth accounting for in your mount's payload; the D-style dovetail and accessory rail come fitted, so the mounting hardware itself is already handled.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eThe two correctors are not interchangeable in spacing.\u003c\/strong\u003e 75 mm for the flattener, 95 mm for the reducer-flattener, measured from different reference surfaces. The 44 mm and 34 mm circles differ with them.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eThe vendor quotes the focuser two ways.\u003c\/strong\u003e The manual specifies a double-speed rack and pinion of 74 mm (3 in) diameter; the product page describes a 3.4-inch linear rail rack-and-pinion with micro focus. Both refer to the same focuser on the same tube.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTwo weights are published.\u003c\/strong\u003e The optical tube is 10.7 kg (25 lbs); the shipping figure of 58.0 lb covers the tube, rings, dovetail, rail, adapter and the foam-lined hard case together.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003e\u003cstrong\u003eFrequently Asked Questions\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003e\u003cstrong\u003eIs it difficult to set up?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eThe optical side is straightforward: the tube arrives in its rings with the D-style dovetail and accessory rail fitted, so mounting is a single clamp. What takes planning is the handling, since 10.7 kg is a two-hand lift onto a saddle at chest height, and the imaging spacing, which is 75 mm with the flattener or 95 mm with the reducer-flattener. Measure the train once and it stays measured.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWill it cover a full-frame sensor?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eWith the field flattener, yes: full illumination across a 44 mm imaging plane, and full frame has a 43 mm diagonal. With the reducer-flattener the circle is 34 mm, which covers APS-C rather than full frame.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWhat mount does it need?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eSomething with headroom well past 10.7 kg once your camera train is attached, and a Losmandy-format saddle to take the D-style bar. Send us your mount model and we will tell you where you will land.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eHow good is it visually?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003e1.16 arc second Rayleigh resolution, limiting magnitude 12.9, and 283x of useful magnification. Back focus greater than 225 mm means a 2-inch diagonal and a binoviewer both reach focus.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWhat is the difference between FPL-53 and ordinary ED glass?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eDispersion. FPL-53 has a lower dispersion figure than common ED types, which is what allows a 120 mm triplet to stay colour-corrected at f\/7 instead of needing a slower focal ratio.\u003c\/p\u003e\n\n\u003ch3\u003e\u003cstrong\u003eBottom Line\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eA 120 mm f\/7 FPL-53 air-spaced triplet with a rotatable 74 mm dual-speed focuser, over 225 mm of back focus, and published corrector options covering 44 mm and 34 mm imaging planes. It is the Esprit EDX package at the aperture where resolution, not just field, is the point.\u003c\/p\u003e","brand":"Sky-Watcher","offers":[{"title":"Default Title","offer_id":53896765079663,"sku":"S11445","price":4580.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/S11445_Esprit120EDX_OTA_LeftFront.jpg?v=1785253740"},{"product_id":"sky-watcher-esprit-150edx-field-flattener","title":"Sky-Watcher Esprit 150EDX Field Flattener","description":"\u003ch3\u003e\u003cstrong\u003eProduct Overview\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eThe Esprit 150EDX Flattener is Sky-Watcher's dedicated field corrector for the Esprit 150EDX super apochromatic refractor. The objective brings light to focus on a slightly curved surface while a camera sensor is flat, and that difference is what turns corner stars into short radial streaks while the centre of the frame is pinpoint. This corrector sits in the imaging train and flattens the focal surface onto the sensor plane.\u003c\/p\u003e\n\u003cp\u003eSky-Watcher publishes a 44 mm corrected image circle for it. A full-frame sensor measures 43.3 mm across the diagonal, so the corrected field encloses full-frame and leaves an APS-C sensor comfortably inside it.\u003c\/p\u003e\n\u003cp\u003eThis part flattens; it does not reduce. Sky-Watcher publishes no reduction factor, no altered focal length and no altered focal ratio for it, so the Esprit 150EDX images at its native figures with this corrector in place. The 0.77x Reducer\/Flattener for the Esprit 150 (S20215) is a separate optic built for the opposite job.\u003c\/p\u003e\n\n\u003ch3\u003e\u003cstrong\u003eWho It's For\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eThis is the corrector Sky-Watcher pairs with the Esprit 150EDX, so it is the right part if you own that telescope and want flat, round stars across a large sensor at the scope's native focal length \u0026amp; ratio.\u003c\/p\u003e\n\u003cp\u003eThe Esprit 150 is the longest tube in the line, and the reason to flatten rather than reduce is image scale: galaxy detail, globular cluster cores, planetary nebulae and small emission knots all benefit from keeping every millimetre of native focal length. If a wider, faster field is what you are after instead, the 0.77x reducer\/flattener for the Esprit 150 is the part built for that.\u003c\/p\u003e\n\n\u003ch3\u003e\u003cstrong\u003eKey Features \u0026amp; Design\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eMatched to the Esprit 150EDX:\u003c\/strong\u003e Sky-Watcher publishes compatibility with the Esprit 150EDX specifically, so the correction is figured for that objective rather than sold as a universal flattener.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e44 mm corrected image circle:\u003c\/strong\u003e covers a full-frame sensor's 43.3 mm diagonal and places APS-C well inside the corrected zone.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFlattening only:\u003c\/strong\u003e with no published reduction factor, the telescope's native focal length and focal ratio carry straight through.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSingle optic in the train:\u003c\/strong\u003e one corrector between focuser and camera, with no separate elements to align against each other.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003e\u003cstrong\u003eOptical \/ Mechanical Design\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003e\u003cstrong\u003eWhat it corrects:\u003c\/strong\u003e field curvature across the Esprit 150EDX imaging field. The symptom it removes is radial elongation of stars toward the frame corners while the centre focuses cleanly.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eCorrected image circle:\u003c\/strong\u003e 44 mm, as published by Sky-Watcher. Sensor coverage follows from that figure — full-frame spans 43.3 mm corner to corner and APS-C roughly 28 mm, so both fall inside the corrected field.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eResulting focal length and focal ratio:\u003c\/strong\u003e Sky-Watcher publishes neither, which is consistent with a flattener that works at native focal length. Only published figures appear here, so no altered numbers are given.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eRequired backfocus and thread interface:\u003c\/strong\u003e the vendor product page carries no backfocus distance in millimetres and no thread size, and links no manual or datasheet. Those two figures set how the corrector spaces to the sensor, so send us your camera, filter drawer or wheel and any adapters and we will work the spacing out with you.\u003c\/p\u003e\n\n\u003ch3\u003e\u003cstrong\u003eRecommended Uses\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eDeep-sky astrophotography at native focal length:\u003c\/strong\u003e galaxies, globular clusters, planetary nebulae and compact nebular detail, where the Esprit 150's image scale is the point.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eLarge-sensor imaging:\u003c\/strong\u003e the 44 mm circle supports full-frame and APS-C cameras, including cooled astronomical CMOS bodies in those formats.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMosaics:\u003c\/strong\u003e flat corners let adjacent panels stitch without a ring of distorted stars at each seam.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eNarrowband and broadband:\u003c\/strong\u003e field curvature is geometric, so the correction holds whatever filter is in front of the sensor.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003e\u003cstrong\u003eCompatibility and Accessory Notes\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eSky-Watcher lists one compatible telescope for this corrector: the Esprit 150EDX. The earlier Esprit 150ED and the other tubes in the range have their own correctors, and refractors from other makers pair with theirs. Send us the exact model printed on your tube and we will confirm which corrector belongs on it.\u003c\/p\u003e\n\u003cp\u003eBecause the thread interface and sensor spacing are not published, the adapter stack between this corrector and your camera cannot be specified from vendor data alone. Tell us your camera model, filter wheel or drawer, and any off-axis guider, and we will map the imaging train and tell you exactly what sits where.\u003c\/p\u003e\n\u003cp\u003eOn the mount side nothing changes: this adds a short optic and roughly a pound behind the focuser rather than altering how the telescope rides.\u003c\/p\u003e\n\n\u003ch3\u003e\u003cstrong\u003eGood to Know Before You Order\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eBackfocus is not published.\u003c\/strong\u003e Sky-Watcher gives no spacing figure in millimetres for this corrector. Corner star shape depends on hitting the correct sensor distance, and we can work that out with you from your camera and adapters.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eThread interface is not published.\u003c\/strong\u003e No thread size appears on the vendor page, so the camera-side connection is confirmed case by case.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePublished for the Esprit 150EDX.\u003c\/strong\u003e The 44 mm figure is stated for that telescope and is not carried across to other models.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eIt is a flattener, not a reducer.\u003c\/strong\u003e Focal length and focal ratio stay at the telescope's native values; the separate 0.77x reducer\/flattener is the part that changes them.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWeight figure is the vendor's shipping weight.\u003c\/strong\u003e Sky-Watcher lists 1.0 lb for this item and publishes no separate optic-only mass in a specification table.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eVendor image note.\u003c\/strong\u003e Sky-Watcher states \"Images subject to change\" on this listing, which is usual for a recently released part.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003e\u003cstrong\u003eFrequently Asked Questions\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003e\u003cstrong\u003eIs it difficult to set up?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eIt is one optic that installs between the focuser and the camera and then stays there. The element that takes attention is the spacing to the sensor, which Sky-Watcher does not publish for this corrector. Send us the camera and adapters you plan to use and we will lay the train out for you.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eDoes it change the focal length or focal ratio?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eSky-Watcher publishes no reduction factor, resulting focal length or resulting focal ratio for it. It flattens the field at the telescope's native figures. The 0.77x Reducer\/Flattener is the part that shortens focal length and speeds the ratio.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWill it cover my full-frame camera?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eThe published corrected image circle is 44 mm and a full-frame sensor measures 43.3 mm on the diagonal, so the sensor sits inside the corrected field. APS-C sits well inside it.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eDoes it fit the Esprit 150ED rather than the 150EDX?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eSky-Watcher publishes compatibility only with the Esprit 150EDX for this part. The Esprit 150ED has its own correctors in the range, including a 0.77x reducer\/flattener. Send us the model on your tube and we will match it.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eHow much does it add to the imaging train?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eSky-Watcher lists 1.0 lb for this item — a small addition behind the focuser alongside the camera, filters and any guider.\u003c\/p\u003e\n\n\u003ch3\u003e\u003cstrong\u003eBottom Line\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eThe dedicated flattener for the Esprit 150EDX, with a published 44 mm corrected circle that keeps stars round across a full-frame sensor at the telescope's native focal length. Sky-Watcher leaves backfocus and thread figures unpublished, so we confirm the spacing against your own camera and adapters and send it out ready to drop into the train.\u003c\/p\u003e","brand":"Sky-Watcher","offers":[{"title":"Default Title","offer_id":53896765112431,"sku":"S20219","price":550.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/150_2.jpg?v=1785253731"},{"product_id":"sky-watcher-0-77x-reducer-flattener-for-esprit-120ed","title":"Sky-Watcher 0.77x Reducer\/Flattener for Esprit 120ED","description":"\u003ch3\u003e\u003cstrong\u003eProduct Overview\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eThe Esprit 120ED Reducer\/Flattener is Sky-Watcher's 0.77x corrector for the Esprit 120ED. It does two jobs in one optic: it flattens the curved focal surface the triplet objective produces so corner stars stay round, and it shortens the system. Sky-Watcher publishes the change as a drop from native f\/7 (840mm) to f\/5.4 (647mm).\u003c\/p\u003e\n\u003cp\u003eThat faster ratio is the reason most people fit one. Sky-Watcher publishes a 68% reduction in exposure time compared with native f\/7 — the same signal arrives in a fraction of the integration, which shows up as more usable subs per night rather than as a change in what the telescope can resolve.\u003c\/p\u003e\n\u003cp\u003eThe field grows with it. Sky-Watcher publishes a 3.18 x 2.12-degree field of view on a full-frame camera and 2.08 x 1.39 degrees on an APS-C crop sensor, with a 34 mm fully illuminated field that the vendor states can handle full frame as well.\u003c\/p\u003e\n\u003cp\u003eThis is the reducing corrector for the Esprit 120ED. The Esprit 120EDX Flattener (S20218) is a different part — it flattens at native focal length and publishes no reduction.\u003c\/p\u003e\n\n\u003ch3\u003e\u003cstrong\u003eWho It's For\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eThis is for Esprit 120ED owners imaging wide targets: large emission nebulae, open clusters with surrounding nebulosity, star fields, and anything that runs off the edge of the frame at 840 mm. At 647 mm and f\/5.4 the same telescope frames a noticeably wider field and gathers it faster.\u003c\/p\u003e\n\u003cp\u003eIt also suits anyone working from a site with limited clear time or heavy light pollution, where the 68% shorter exposure Sky-Watcher publishes translates directly into finishing a target in fewer nights.\u003c\/p\u003e\n\u003cp\u003eIf the goal is maximum image scale on small targets instead — galaxies, globulars, planetary nebulae — a plain flattener at native focal length is the part that serves that.\u003c\/p\u003e\n\n\u003ch3\u003e\u003cstrong\u003eKey Features \u0026amp; Design\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003e0.77x reduction, published end to end:\u003c\/strong\u003e Sky-Watcher states the result as f\/7 (840mm) dropping to f\/5.4 (647mm) on the Esprit 120ED, so the working figures are the vendor's own rather than an estimate.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eReducer and flattener in one optic:\u003c\/strong\u003e field curvature correction and focal reduction happen in the same unit, so only one element joins the imaging train.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e34 mm fully illuminated field:\u003c\/strong\u003e the vendor's published figure, with the note that it can handle full frame as well.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTwo backfocus configurations:\u003c\/strong\u003e 95 mm back-focus as supplied, or 55 mm with the back focus spacer and M48 ring installed — the 55 mm figure is the standard astro-camera spacing.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eBuilt-in 2\" filter cell:\u003c\/strong\u003e a 2-inch filter threads into the corrector itself, putting the filter in the light path without a separate drawer or spacer stack.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePublished fields of view:\u003c\/strong\u003e 3.18 x 2.12 degrees on full frame, 2.08 x 1.39 degrees on APS-C.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003e\u003cstrong\u003eOptical \/ Mechanical Design\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003e\u003cstrong\u003eWhat it corrects:\u003c\/strong\u003e field curvature across the Esprit 120ED imaging field, combined with a 0.77x focal reduction. Without a corrector, stars in the corners stretch radially while the frame centre focuses cleanly; this optic flattens that surface onto the sensor plane and shortens the system at the same time.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eResulting focal length and focal ratio:\u003c\/strong\u003e Sky-Watcher publishes the change as native f\/7 (840mm) to f\/5.4 (647mm). Both figures are the vendor's, stated for the Esprit 120ED specifically.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eCorrected image circle:\u003c\/strong\u003e 34 mm fully illuminated, with Sky-Watcher noting it can handle full frame as well. A full-frame sensor's 43.3 mm diagonal sits outside the 34 mm fully illuminated circle, so the far corners of a full-frame chip fall in the region the vendor describes as usable rather than fully illuminated; an APS-C sensor at roughly 28 mm diagonal sits entirely inside it. The published fields of view follow from that — 3.18 x 2.12 degrees full frame, 2.08 x 1.39 degrees APS-C.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eRequired backfocus:\u003c\/strong\u003e 95 mm as supplied, or 55 mm when the back focus spacer and M48 ring are installed. 55 mm is the distance most cooled astronomical cameras and filter wheels are built around, so the reconfigured setting is the one most imaging trains land on.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eThread interface:\u003c\/strong\u003e M48, by way of the M48 ring that pairs with the 55 mm back focus configuration.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eFilter mounting:\u003c\/strong\u003e the 2\" filter cell is built into the corrector, so a 2-inch filter sits inside the reduced light path rather than adding length to the train.\u003c\/p\u003e\n\n\u003ch3\u003e\u003cstrong\u003eRecommended Uses\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eWide-field deep-sky astrophotography:\u003c\/strong\u003e large emission and reflection nebulae, cluster-plus-nebulosity fields and Milky Way regions that overflow the native 840 mm frame.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eShort-session and light-polluted imaging:\u003c\/strong\u003e the published 68% exposure reduction against native f\/7 puts more finished data into each clear night.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eNarrowband work:\u003c\/strong\u003e the faster ratio offsets the transmission cost of narrow filters, and the built-in 2\" cell holds the filter in the light path.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAPS-C and full-frame imaging:\u003c\/strong\u003e APS-C sits inside the 34 mm fully illuminated field; full frame is covered by the vendor's stated capability with the published 3.18 x 2.12-degree frame.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003e\u003cstrong\u003eCompatibility and Accessory Notes\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eSky-Watcher publishes this corrector for the Esprit 120ED, and the reduction figures — f\/7 (840mm) to f\/5.4 (647mm) — are stated for that telescope. Other Esprit models pair with their own correctors, including the separate Esprit 120EDX Flattener, and refractors from other makers have their own. Send us the exact model printed on your tube and we will confirm which corrector belongs on it.\u003c\/p\u003e\n\u003cp\u003eThe two published backfocus settings shape the rest of the train. At 55 mm, with the back focus spacer and M48 ring installed, the corrector meets the standard most cooled astro cameras and filter wheels are dimensioned for. At 95 mm as supplied, the extra distance has to be filled by whatever sits between corrector and sensor. Send us your camera, filter wheel or drawer, off-axis guider and any adapters, and we will add the train up with you and confirm which configuration your setup wants.\u003c\/p\u003e\n\u003cp\u003eFilters thread into the built-in 2\" cell, so a 2-inch filter needs no separate drawer. Cameras with their own internal filter wheel simply leave that cell empty.\u003c\/p\u003e\n\n\u003ch3\u003e\u003cstrong\u003eGood to Know Before You Order\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eThe published figures are for the Esprit 120ED.\u003c\/strong\u003e 840mm to 647mm and f\/7 to f\/5.4 are stated for that telescope. Other refractors reduce by their own numbers with their own correctors.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eBackfocus decides corner star shape.\u003c\/strong\u003e The corrector delivers 95 mm as supplied and 55 mm with the back focus spacer and M48 ring installed; the imaging train is built to whichever of those two figures you use.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e34 mm is the fully illuminated field.\u003c\/strong\u003e Sky-Watcher states it can handle full frame as well, so a full-frame sensor's outer corners lie beyond the fully illuminated circle in the region the vendor describes as usable.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFilter cell takes 2-inch filters.\u003c\/strong\u003e The built-in cell is sized for 2\" filters; other filter sizes go elsewhere in the train.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eThis is the reducing corrector, not the flattener.\u003c\/strong\u003e The Esprit 120EDX Flattener is a separate part that works at native focal length.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eVendor publishes no barcode for this SKU.\u003c\/strong\u003e The UPC we carry is 050234202091.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eVendor lists 2.0 lb for this item.\u003c\/strong\u003e That is the published weight; no separate optic-only mass appears in a specification table.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003e\u003cstrong\u003eFrequently Asked Questions\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003e\u003cstrong\u003eIs it difficult to set up?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eThe optic threads into the imaging train once and stays there. The decision that matters is which backfocus you build to — 95 mm as supplied, or 55 mm with the back focus spacer and M48 ring installed — and then adding the camera, filter wheel and adapters up to that number. Send us your components and we will do that arithmetic with you.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWhat focal length and focal ratio do I end up with?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eSky-Watcher publishes the Esprit 120ED as dropping from native f\/7 (840mm) to f\/5.4 (647mm) with this reducer\/flattener fitted.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eHow much faster is it in practice?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eSky-Watcher publishes a 68% reduction in exposure time compared with native f\/7 for the same result.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWill it cover a full-frame sensor?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eSky-Watcher publishes a 34 mm fully illuminated field and states it can handle full frame as well, quoting a 3.18 x 2.12-degree field of view on a full-frame camera and 2.08 x 1.39 degrees on APS-C.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWhat thread does it use?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eM48, via the M48 ring that goes with the 55 mm back focus configuration.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eCan I use filters with it?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eYes — there is a built-in 2\" filter cell for mounting filters, so a 2-inch filter sits in the light path without a separate drawer.\u003c\/p\u003e\n\n\u003ch3\u003e\u003cstrong\u003eBottom Line\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eSky-Watcher's own 0.77x corrector for the Esprit 120ED: f\/7 (840mm) becomes f\/5.4 (647mm), exposure time drops by a published 68%, the field opens to 3.18 x 2.12 degrees on full frame, and a 2\" filter threads straight into the corrector. Tell us what camera and filters you are running and we will confirm the 55 mm or 95 mm spacing with you before it ships.\u003c\/p\u003e","brand":"Sky-Watcher","offers":[{"title":"Default Title","offer_id":53896771436655,"sku":"S20209","price":730.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/S20209_Esprit120_RedFlat_web.jpg?v=1785253815"},{"product_id":"sky-watcher-esprit-150edx-super-apo-triplet-refractor","title":"Sky-Watcher Esprit 150EDX Super APO Triplet Refractor","description":"\u003ch3\u003e\u003cstrong\u003eProduct Overview\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eThe Esprit 150EDX is the largest optical tube in Sky-Watcher's Esprit EDX astrograph line: a 150 mm air-spaced triplet apochromat working at 1050 mm of focal length and f\/7. The three-element, laboratory-matched objective uses extra-low dispersion glass, and every surface carries Sky-Watcher's Metallic High-Transmission Coatings (MHTC). For this aperture Sky-Watcher publishes 0.77 arc seconds Dawes resolution, 0.93 arc seconds Rayleigh, a limiting stellar magnitude of 13.4, and light grasp 459x that of the human eye.\u003c\/p\u003e\n\u003cp\u003eWhat ships is the optical tube assembly with mounting rings, dovetail plate, camera adapter and a foam-lined hard case. The mount is chosen separately, and at 15 kg (32 lbs) of tube weight the mount choice is the main planning decision on this scope.\u003c\/p\u003e\n\n\u003ch3\u003e\u003cstrong\u003eWho It's For\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eThis is a good match if you image at longer focal lengths and want refractor star shape rather than a mirror system's diffraction pattern. At 1050 mm, galaxy cores, globular clusters and small planetary nebulae come up at a scale most 400-600 mm astrographs cannot reach, while f\/7 keeps exposures workable.\u003c\/p\u003e\n\u003cp\u003eIt is equally at home visually. Sky-Watcher publishes more than 170 mm (6.7 in) of visual back focus, which accommodates a 2-inch diagonal and binoviewers without adapters that eat into travel, and a useful magnification range of 21x to 354x covers everything from full-frame nebulae to high-power planetary work.\u003c\/p\u003e\n\u003cp\u003eAstrophotographers pairing it with a large German equatorial - and observers who want one refractor that does deep-sky imaging and planetary viewing without compromise - are the natural buyers here.\u003c\/p\u003e\n\n\u003ch3\u003e\u003cstrong\u003eKey Features \u0026amp; Design\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003e150 mm f\/7 air-spaced triplet apochromat:\u003c\/strong\u003e three matched elements including extra-low dispersion glass, so bright stars and lunar limbs come through without the violet fringe a doublet leaves behind.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMetallic High-Transmission Coatings (MHTC):\u003c\/strong\u003e full multi-coating on every air-to-glass surface, which is where the published 459x light-gathering figure comes from.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e3-inch CNC-machined rotatable dual-speed focuser:\u003c\/strong\u003e a linear power focuser with 1:11 fine reduction. The drawtube is a linear track rather than a rack riding on a shaft, so a 15 kg imaging train does not introduce image shift at the moment of focus.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCamera Angle Adjuster:\u003c\/strong\u003e sits at the end of the drawtube and rotates the camera or eyepiece to frame a target, leaving the focuser body and its balance untouched.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eRotatable focuser body:\u003c\/strong\u003e standard on the 100, 120 and 150 EDX, so the focus knobs can be indexed to wherever your hand falls at the mount.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e44 mm fully illuminated field with the field flattener:\u003c\/strong\u003e that covers a full-frame 35 mm sensor's 43.3 mm diagonal.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMore than 170 mm visual back focus:\u003c\/strong\u003e room for a 2-inch diagonal, a binoviewer, or a filter wheel and off-axis guider stack.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eIncluded in the box:\u003c\/strong\u003e mounting rings, dovetail plate, camera adapter and a foam-lined hard case.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003e\u003cstrong\u003eOptical \/ Mechanical Design\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eThe objective is a three-element, air-spaced super-apochromatic assembly. Air spacing lets Sky-Watcher tune the gaps between elements during assembly rather than accepting whatever an oiled or cemented stack gives, and the matched-assembly process means the three elements in your tube were figured and tested together. The practical result is the 0.77 arc second Dawes figure holding across the field instead of only at centre, and colour that stays neutral on Vega or a first-quarter Moon.\u003c\/p\u003e\n\u003cp\u003eMechanically the interesting part is the focuser. A 3-inch drawtube is wide enough that the light cone from a 150 mm f\/7 objective clears it without vignetting at the corners of a full-frame sensor, and the linear-track design carries the load on rails rather than on a pinion contact patch. The 1:11 fine ratio gives roughly a tenth of a turn of drawtube travel per full turn of the fine knob, which matters when critical focus at f\/7 on a 150 mm aperture is a few tens of microns deep.\u003c\/p\u003e\n\u003cp\u003eThe tube measures 92 cm (36 in) with the dew cap retracted, and weighs 15 kg (32 lbs). Sky-Watcher's own carton for the complete package, including the hard case, is listed at 77 lb.\u003c\/p\u003e\n\n\u003ch3\u003e\u003cstrong\u003eRecommended Uses\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eLong-focal-length deep-sky imaging:\u003c\/strong\u003e 1050 mm at f\/7 across a flattened 44 mm circle, for galaxies, globulars and compact nebulae.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eNarrowband work:\u003c\/strong\u003e the apochromatic correction means Ha, OIII and SII sub-frames land on the same focus point, so filter-offset chasing largely disappears.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eHigh-resolution lunar and planetary viewing:\u003c\/strong\u003e 354x highest useful magnification with an unobstructed aperture.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDouble-star observing:\u003c\/strong\u003e 0.77 arc seconds Dawes.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWide-field visual sweeping:\u003c\/strong\u003e 21x lowest useful magnification through a 2-inch diagonal.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003e\u003cstrong\u003eCompatibility and Accessory Notes\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eThe Esprit 150EDX Flattener is the matched corrector for this tube and is sold separately. Sky-Watcher specifies the sensor sitting at exactly 100 mm from the back of the flattener, or 95 mm from the edge of the lens mount - corner star shape across the 44 mm circle depends on hitting that number, and it is set with spacers between the flattener and the camera. These figures are published for the Esprit 150EDX; other Esprit apertures pair with their own flatteners, so send us your model and we will confirm the right one.\u003c\/p\u003e\n\u003cp\u003eThe camera adapter supplied with the tube handles a straightforward DSLR or mirrorless attachment. For a filter wheel, off-axis guider and cooled camera stack, the spacing arithmetic changes - send us the parts list and we will work out the spacer chain with you before you order.\u003c\/p\u003e\n\u003cp\u003eVisually, the published back focus of more than 170 mm accepts a 2-inch star diagonal and standard eyepieces, and leaves enough travel for a binoviewer's optical path.\u003c\/p\u003e\n\u003cp\u003eThe tube ships with mounting rings and a dovetail plate. At 15 kg before a camera, imaging mounts in the EQ6-R \/ EQ8 class are the usual pairing; tell us what you are mounting on and we will confirm the headroom.\u003c\/p\u003e\n\n\u003ch3\u003e\u003cstrong\u003eGood to Know Before You Order\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eThis is an optical tube assembly.\u003c\/strong\u003e Mounting rings, dovetail plate, camera adapter and hard case are included; a mount, tripod and eyepieces are not.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTube weight is 15 kg (32 lbs).\u003c\/strong\u003e With a camera, filter wheel and guider attached the imaging payload lands meaningfully higher, which is worth accounting for against your mount's rating.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eThe field flattener is a separate purchase.\u003c\/strong\u003e The 44 mm fully illuminated field is the figure published with the flattener in place.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSky-Watcher's spec sheet does not name the specific ED glass type for this model.\u003c\/strong\u003e Their published description states laboratory-matched lens assemblies including extra-low dispersion elements; we have not carried a glass code across from another Esprit aperture.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eShipping weight is 77 lb for the complete package.\u003c\/strong\u003e The hard case and packaging account for the difference from the 15 kg tube figure.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFree shipping applies to this item\u003c\/strong\u003e per Sky-Watcher's listing.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003e\u003cstrong\u003eFrequently Asked Questions\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003e\u003cstrong\u003eIs it difficult to set up?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eThe optical assembly arrives finished - there is no collimation to perform and no mirror to align. Setup is mounting rings onto the dovetail, dovetail into the saddle, and balancing. The one part that takes real handling is the tube itself: 15 kg over 92 cm is a two-hand lift onto a saddle, and most owners settle into a routine of mounting the tube before the counterweights go on.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWhat is the difference between the Esprit EDX and the older Esprit ED?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eThe EDX generation adds the Camera Angle Adjuster at the drawtube and, on the 100, 120 and 150, a rotatable focuser body. The objective carries Sky-Watcher's MHTC multi-coating.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eDo I need the flattener for visual observing?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eNo. The flattener corrects field curvature across a camera sensor. For eyepiece use the tube goes straight to a 2-inch diagonal, with more than 170 mm of back focus available.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWill it cover a full-frame sensor?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eWith the matched flattener, the fully illuminated field is 44 mm - larger than the 43.3 mm diagonal of a 35 mm full-frame sensor.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eCan it be used for planetary imaging?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eYes. 1050 mm native focal length with an unobstructed 150 mm aperture, and a published highest useful magnification of 354x, suits lunar and planetary capture directly or with a Barlow.\u003c\/p\u003e\n\n\u003ch3\u003e\u003cstrong\u003eBottom Line\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eA 150 mm f\/7 triplet apochromat with a 3-inch rotatable dual-speed focuser, a 44 mm flattened image circle and better than 170 mm of visual back focus - shipped as an optical tube with rings, dovetail, camera adapter and hard case. It is the top of the Esprit EDX range, and it does long-focal-length imaging and high-power visual work with the same optics. If you would like us to confirm the mount pairing or the imaging-train spacing for your camera, send us the details and we will map it out.\u003c\/p\u003e","brand":"Sky-Watcher","offers":[{"title":"Default Title","offer_id":53896772288623,"sku":"S11455","price":6670.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/S11455_Esprit150EDX_OTA_LeftFront.jpg?v=1785253841"},{"product_id":"sky-watcher-0-77x-reducer-flattener-for-esprit-150ed","title":"Sky-Watcher 0.77x Reducer\/Flattener for Esprit 150ED","description":"\u003ch3\u003e\u003cstrong\u003eProduct Overview\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eThe Esprit 150ED Reducer\/Flattener is Sky-Watcher's 0.77x corrector for the Esprit 150ED. It flattens the curved focal surface the triplet objective produces, so stars stay round out to the corners, and shortens the system at the same time. Sky-Watcher publishes the change as a drop from native f\/7 (1050mm) to f\/5.4 (810mm).\u003c\/p\u003e\n\u003cp\u003eOn the largest tube in the Esprit line, that shift matters most in time. Sky-Watcher publishes a 68% reduction in exposure time compared with native f\/7 — a 1050 mm f\/7 system is a demanding place to collect photons, and f\/5.4 turns the same target into a materially shorter project.\u003c\/p\u003e\n\u003cp\u003eThe frame widens with the reduction. Sky-Watcher publishes a 2.54 x 1.7-degree field of view on a full-frame camera and 1.66 x 1.11 degrees on APS-C, backed by a 36 mm fully illuminated field the vendor states is compatible with both APS-C and full frame sensors.\u003c\/p\u003e\n\u003cp\u003eThis is the reducing corrector for the Esprit 150ED. The Esprit 150EDX Flattener (S20219) is a separate part that flattens at native focal length and publishes no reduction.\u003c\/p\u003e\n\n\u003ch3\u003e\u003cstrong\u003eWho It's For\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eThis is for Esprit 150ED owners who want the tube's aperture without its native 1050 mm framing — large emission nebulae, extended cluster fields, bright galaxy groups, anything that crowds the edges at f\/7. At 810 mm and f\/5.4 the same telescope covers 2.54 x 1.7 degrees on a full-frame sensor.\u003c\/p\u003e\n\u003cp\u003eIt also fits anyone whose clear nights are the scarce resource. The published 68% exposure reduction against native f\/7 is the difference between finishing a narrowband target over a season and finishing it over a few weeks.\u003c\/p\u003e\n\u003cp\u003eIf maximum image scale on small targets is the aim instead, a flattener working at the native 1050 mm is the part for that.\u003c\/p\u003e\n\n\u003ch3\u003e\u003cstrong\u003eKey Features \u0026amp; Design\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003e0.77x reduction, published end to end:\u003c\/strong\u003e Sky-Watcher states the result as f\/7 (1050mm) dropping to f\/5.4 (810mm) on the Esprit 150ED, so both working figures come from the vendor.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eReducer and flattener in one optic:\u003c\/strong\u003e curvature correction and focal reduction in a single unit, adding one element to the imaging train.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e36 mm fully illuminated field:\u003c\/strong\u003e Sky-Watcher's published figure, stated as compatible with both APS-C and full frame sensors.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTwo backfocus configurations:\u003c\/strong\u003e 90 mm back-focus as supplied, or 55 mm with the back focus spacer and M48 ring installed — 55 mm being the spacing most cooled astro cameras are built around.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eBuilt-in 2\" filter cell:\u003c\/strong\u003e a 2-inch filter mounts into the light path inside the corrector rather than in a separate drawer.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eComplete in the box:\u003c\/strong\u003e Sky-Watcher lists the reducer, metal thread-on caps, back focus spacer and M48 thread adapter as included.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003e\u003cstrong\u003eOptical \/ Mechanical Design\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003e\u003cstrong\u003eWhat it corrects:\u003c\/strong\u003e field curvature across the Esprit 150ED imaging field, combined with a 0.77x focal reduction. Uncorrected, the corners of a large sensor show stars stretched radially while the frame centre is sharp; this optic flattens that surface onto the sensor plane and shortens the system in the same pass.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eResulting focal length and focal ratio:\u003c\/strong\u003e Sky-Watcher publishes the change as native f\/7 (1050mm) to f\/5.4 (810mm), stated for the Esprit 150ED specifically.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eCorrected image circle:\u003c\/strong\u003e 36 mm fully illuminated, which the vendor states is compatible with both APS-C and full frame sensors. An APS-C sensor's roughly 28 mm diagonal sits inside the fully illuminated circle; a full-frame sensor spans 43.3 mm, so its extreme corners fall outside the 36 mm figure in the region Sky-Watcher covers with the full-frame compatibility statement. The published fields follow — 2.54 x 1.7 degrees full frame, 1.66 x 1.11 degrees APS-C.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eRequired backfocus:\u003c\/strong\u003e 90 mm as supplied, or 55 mm with the back focus spacer and M48 ring installed. 55 mm is the distance most cooled astronomical cameras and filter wheels are dimensioned to, so that is where most imaging trains settle.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eThread interface:\u003c\/strong\u003e M48, via the included M48 thread adapter that pairs with the 55 mm back focus configuration.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eFilter mounting:\u003c\/strong\u003e the built-in 2\" filter cell holds a 2-inch filter in the light path without adding a drawer or extra spacers to the train.\u003c\/p\u003e\n\n\u003ch3\u003e\u003cstrong\u003eRecommended Uses\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eWide-field deep-sky astrophotography:\u003c\/strong\u003e large emission and reflection nebulae, extended cluster fields and galaxy groups that run past the frame at 1050 mm.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eNarrowband imaging:\u003c\/strong\u003e the faster f\/5.4 ratio offsets the transmission cost of narrow filters, and the built-in 2\" cell carries the filter in the light path.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eLimited clear-sky sites:\u003c\/strong\u003e the published 68% exposure reduction against native f\/7 puts more finished signal into each usable night.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFull-frame and APS-C imaging:\u003c\/strong\u003e the 36 mm fully illuminated field is published as compatible with both, at 2.54 x 1.7 and 1.66 x 1.11 degrees respectively.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003e\u003cstrong\u003eCompatibility and Accessory Notes\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eSky-Watcher publishes this corrector for the Esprit 150ED, and the f\/7 (1050mm) to f\/5.4 (810mm) figures are stated for that telescope. Other Esprit models pair with their own correctors — including the separate Esprit 150EDX Flattener — and refractors from other makers have theirs. Send us the exact model printed on your tube and we will confirm which corrector belongs on it.\u003c\/p\u003e\n\u003cp\u003eThe box covers most of the spacing work: reducer, metal thread-on caps, back focus spacer and M48 thread adapter are all included. With the spacer and M48 adapter fitted, the corrector presents 55 mm of back focus, which is what a typical cooled camera plus filter wheel is built to consume. As supplied without them, it presents 90 mm, and that distance is filled by whatever sits between corrector and sensor.\u003c\/p\u003e\n\u003cp\u003eSend us your camera, filter wheel or drawer, off-axis guider and adapters and we will add the imaging train up with you and confirm which of the two configurations your setup wants. Filters thread into the built-in 2\" cell; cameras with an internal filter wheel simply leave that cell empty.\u003c\/p\u003e\n\n\u003ch3\u003e\u003cstrong\u003eGood to Know Before You Order\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eThe published figures are for the Esprit 150ED.\u003c\/strong\u003e 1050mm to 810mm and f\/7 to f\/5.4 are stated for that telescope. Other refractors reduce by their own numbers with their own correctors.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eBackfocus sets corner star shape.\u003c\/strong\u003e The corrector presents 90 mm as supplied and 55 mm with the back focus spacer and M48 ring installed; the rest of the train is built to whichever figure you use.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e36 mm is the fully illuminated field.\u003c\/strong\u003e Sky-Watcher states compatibility with both APS-C and full frame sensors, with a full-frame sensor's outer corners lying beyond the 36 mm fully illuminated circle.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFilter cell takes 2-inch filters.\u003c\/strong\u003e The built-in cell is sized for 2\" filters; other filter sizes go elsewhere in the train.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eThis is the reducing corrector, not the flattener.\u003c\/strong\u003e The Esprit 150EDX Flattener is a separate part working at native focal length.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eVendor publishes no barcode for this SKU.\u003c\/strong\u003e The UPC we carry is 050234202152.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eVendor lists 2.0 lb for this item.\u003c\/strong\u003e That is the published weight; no separate optic-only mass appears in a specification table.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003e\u003cstrong\u003eFrequently Asked Questions\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003e\u003cstrong\u003eIs it difficult to set up?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eThe reducer threads into the imaging train once and stays there, and the parts that set the spacing — the back focus spacer and the M48 thread adapter — come in the box. The one decision is which backfocus you build to, 90 mm or 55 mm, and then adding camera, filter wheel and adapters up to that figure. Send us your components and we will do that arithmetic with you.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWhat focal length and focal ratio do I end up with?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eSky-Watcher publishes the Esprit 150ED as dropping from native f\/7 (1050mm) to f\/5.4 (810mm) with this reducer\/flattener fitted.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eHow much time does it save?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eSky-Watcher publishes a 68% reduction in exposure time compared with native f\/7.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWill it cover a full-frame sensor?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eSky-Watcher publishes a 36 mm fully illuminated field described as compatible with both APS-C and full frame sensors, quoting 2.54 x 1.7 degrees on a full-frame camera and 1.66 x 1.11 degrees on APS-C.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWhat comes in the box?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eSky-Watcher lists the reducer, metal thread-on caps, back focus spacer and M48 thread adapter.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eCan I use filters with it?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eYes — a built-in 2\" filter cell mounts filters into the light path, so a 2-inch filter needs no separate drawer.\u003c\/p\u003e\n\n\u003ch3\u003e\u003cstrong\u003eBottom Line\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eSky-Watcher's own 0.77x corrector for the Esprit 150ED: f\/7 (1050mm) becomes f\/5.4 (810mm), exposure time drops by a published 68%, the frame opens to 2.54 x 1.7 degrees on full frame, and the back focus spacer, M48 adapter and thread-on caps are in the box. Tell us what camera and filters you run and we will confirm the 55 mm or 90 mm spacing with you before it ships.\u003c\/p\u003e","brand":"Sky-Watcher","offers":[{"title":"Default Title","offer_id":53896779858031,"sku":"S20215","price":730.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/S20215_Esprit150_RedFlat_web.jpg?v=1785253906"},{"product_id":"sky-watcher-esprit-70edx-evostar-100edx-field-flattener","title":"Sky-Watcher Esprit 70EDX \/ Evostar 100EDX Field Flattener","description":"\u003ch3\u003e\u003cstrong\u003eProduct Overview\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eThis is Sky-Watcher's dedicated field corrector for two telescopes: the Esprit 70EDX and the Evostar 100EDX. A refractor objective brings light to focus on a gently curved surface; a camera sensor is flat. The flattener resolves that mismatch, so stars hold their shape out to the frame edges instead of drawing short radial streaks in the corners while the centre stays sharp.\u003c\/p\u003e\n\u003cp\u003eSky-Watcher publishes it as a 1.0X flattener with a 44 mm corrected image circle. The 1.0X figure means it corrects without reducing: focal length and focal ratio stay at the telescope's native values. The 44 mm circle encloses the 43.3 mm diagonal of a full-frame sensor and covers APS-C with margin to spare, so framing decisions come down to focal length rather than to how much of the sensor the corrector actually reaches.\u003c\/p\u003e\n\u003cp\u003eThe dual fitment is worth reading carefully, because Sky-Watcher's naming runs close together here. This part is published for the \u003cstrong\u003eEvostar\u003c\/strong\u003e 100EDX — the ED doublet. The \u003cstrong\u003eEsprit\u003c\/strong\u003e 100EDX, the super-apochromatic triplet, has its own corrector (S20217).\u003c\/p\u003e\n\n\u003ch3\u003e\u003cstrong\u003eWho It's For\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eThis is the corrector Sky-Watcher pairs with the Esprit 70EDX and the Evostar 100EDX, and it is the right part if you own either telescope and want flat, round stars across a large sensor at the scope's native focal length and ratio.\u003c\/p\u003e\n\u003cp\u003eOn the Esprit 70EDX — published by Sky-Watcher as 70 mm aperture, 455 mm focal length, f\/6.5 — that means very wide fields with corners that hold up: large emission nebulae, star fields, comets, mosaics. On the Evostar 100EDX doublet it means a longer-focal-length field with the same corner correction across a full-frame sensor.\u003c\/p\u003e\n\n\u003ch3\u003e\u003cstrong\u003eKey Features \u0026amp; Design\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eMatched to two telescopes:\u003c\/strong\u003e Sky-Watcher publishes compatibility with the Esprit 70EDX and the Evostar 100EDX. The correction is computed for those objectives rather than sold as a universal flattener.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e1.0X flattener:\u003c\/strong\u003e no reduction. The telescope's native focal length and focal ratio carry through the corrector unchanged.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e44 mm corrected image circle:\u003c\/strong\u003e the published figure covers a full-frame sensor's 43.3 mm diagonal and leaves APS-C well inside the corrected zone.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSingle-piece corrector:\u003c\/strong\u003e one optic in the imaging train between focuser and camera, with no separate elements to align.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOne part for a triplet and a doublet:\u003c\/strong\u003e Sky-Watcher publishes the same corrector against the 70 mm Esprit triplet and the 100 mm Evostar doublet, so a two-telescope setup built from those models needs one flattener rather than two.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003e\u003cstrong\u003eOptical \/ Mechanical Design\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003e\u003cstrong\u003eWhat it corrects:\u003c\/strong\u003e field curvature across the imaging field of the Esprit 70EDX and the Evostar 100EDX. The visible symptom it removes is corner stars that elongate radially, pointing away from the frame centre, while the middle of the frame focuses cleanly.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eCorrected image circle:\u003c\/strong\u003e 44 mm, as published by Sky-Watcher. Sensor coverage follows directly from that number — a full-frame sensor measures 43.3 mm corner to corner and an APS-C sensor roughly 28 mm, so both sit inside the corrected field.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eMagnification factor:\u003c\/strong\u003e 1.0X. Sky-Watcher publishes no reduction, so the Esprit 70EDX continues to image at its published 455 mm and f\/6.5 with this part in the train, and the Evostar 100EDX at its own native figures.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eRequired backfocus and thread interface:\u003c\/strong\u003e Sky-Watcher does not publish a backfocus distance in millimetres or a thread size for this corrector on its product page, and no manual or datasheet is linked there. Those two numbers determine how the corrector spaces to your sensor, and corner star shape is what depends on getting the spacing right. Send us your camera, filter drawer or filter wheel and any adapters and we will lay the train out with you before you order.\u003c\/p\u003e\n\n\u003ch3\u003e\u003cstrong\u003eRecommended Uses\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eWide-field deep-sky astrophotography:\u003c\/strong\u003e on the Esprit 70EDX at 455 mm, large emission nebulae, open clusters, comets and star fields fill the frame with corners that stay clean.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eLonger-focal-length imaging on the Evostar 100EDX:\u003c\/strong\u003e the same corner correction applied to the doublet's field.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eLarge-sensor imaging:\u003c\/strong\u003e the 44 mm circle supports full-frame and APS-C cameras, including cooled astronomical CMOS bodies in those formats.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMosaic panels:\u003c\/strong\u003e flat corners let adjacent panels blend without a ring of distorted stars at every seam.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eNarrowband and broadband alike:\u003c\/strong\u003e field curvature is a geometric error, so the correction applies regardless of the filter in front of the sensor.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003e\u003cstrong\u003eCompatibility and Accessory Notes\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eSky-Watcher lists two compatible telescopes for this corrector: the Esprit 70EDX and the Evostar 100EDX. The name similarity across their range is the thing to watch — the Esprit 100EDX triplet takes S20217, the Esprit 120EDX takes S20218 and the Esprit 150EDX takes S20219, each published against its own tube. Tell us the exact model printed on your telescope and we will confirm which corrector belongs on it.\u003c\/p\u003e\n\u003cp\u003eThe vendor does not publish the thread interface or the spacing distance to the sensor, so the adapters between this corrector and your camera cannot be specified from published data. Send us your camera model, filter wheel or drawer, and any off-axis guider in the train, and we will map the imaging train and tell you exactly what sits between the two.\u003c\/p\u003e\n\u003cp\u003eNothing about this part changes the mount side of the setup: it adds a short optic and roughly a pound behind the focuser rather than changing how the telescope mounts.\u003c\/p\u003e\n\n\u003ch3\u003e\u003cstrong\u003eGood to Know Before You Order\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eBackfocus is not published.\u003c\/strong\u003e Sky-Watcher gives no spacing figure in millimetres for this corrector. Corner star shape depends on hitting the correct sensor distance, and we can work that out with you from your specific camera and adapters.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eThread interface is not published.\u003c\/strong\u003e No thread size appears on the vendor page, so the camera-side connection is confirmed case by case rather than assumed.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eEvostar 100EDX, not Esprit 100EDX.\u003c\/strong\u003e The 100 mm telescope named for this part is the Evostar doublet. The Esprit 100EDX triplet is served by S20217.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eThe 44 mm figure is published for these two telescopes.\u003c\/strong\u003e Other refractors pair with their own correctors, and the figure is not carried across to them.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eIt is a flattener, not a reducer.\u003c\/strong\u003e Sky-Watcher publishes 1.0X, so focal length and focal ratio stay at each telescope's native values.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eBox contents are not published.\u003c\/strong\u003e The vendor states no spacer, adapter or case as supplied with the corrector.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWeight figure is the vendor's shipping weight.\u003c\/strong\u003e Sky-Watcher lists 1.0 lb for this item and publishes no separate optic-only mass in a specification table.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003e\u003cstrong\u003eFrequently Asked Questions\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003e\u003cstrong\u003eIs it difficult to set up?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003ePhysically it is one optic that goes into the imaging train between the focuser and the camera, and it stays there. The part that takes attention is the spacing to the sensor, which Sky-Watcher does not publish for this corrector. Send us the camera and adapters you plan to use and we will lay out the train for you.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eDoes it fit both telescopes, or do I need two?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eSky-Watcher publishes this one corrector against both the Esprit 70EDX and the Evostar 100EDX. If you own both, this is the single part for the pair.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eDoes it change the focal length or focal ratio?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eNo. It is published as a 1.0X flattener, so the Esprit 70EDX images at its native 455 mm and f\/6.5 and the Evostar 100EDX at its own native figures.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWill it cover my full-frame camera?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eThe published corrected image circle is 44 mm and a full-frame sensor measures 43.3 mm across the diagonal, so the sensor sits inside the corrected field. APS-C sits well inside it.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eI have an Esprit 100EDX — is this the one?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eThe 100 mm telescope Sky-Watcher names here is the Evostar 100EDX doublet. For the Esprit 100EDX triplet the published corrector is S20217. Send us the model printed on your tube and we will match it.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWhat weight does it add to the imaging train?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eSky-Watcher lists 1.0 lb for this item. It is a small addition behind the focuser next to the camera, filters and any guider.\u003c\/p\u003e\n\n\u003ch3\u003e\u003cstrong\u003eBottom Line\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eA dedicated 1.0X flattener published for both the Esprit 70EDX and the Evostar 100EDX, with a 44 mm corrected circle — enough to keep stars round across a full-frame sensor at each telescope's native focal length. Sky-Watcher leaves the backfocus and thread figures unpublished, so we confirm the spacing with you against your own camera and adapters and send it out ready to drop into the train.\u003c\/p\u003e","brand":"Sky-Watcher","offers":[{"title":"Default Title","offer_id":53896786083951,"sku":"S20216","price":310.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/100_2_c036ec1b-e071-4037-9437-5adb55294a87.jpg?v=1785253987"}],"url":"https:\/\/ontariotelescope.com\/collections\/skywatcher-esprit.oembed","provider":"Ontario Telescope and Accessories","version":"1.0","type":"link"}