{"title":"Extension Tubes \u0026 Spacers","description":"\u003cp\u003eFixed-length tubes and spacer rings for setting back focus. Most flatteners and reducers want a specific distance from their rear element to the sensor — these are how you hit it.\u003c\/p\u003e\u003cp\u003eGoods ship factory-sealed. Send us your flattener, camera and filter thickness and we'll work the spacing out with you before you order.\u003c\/p\u003e","products":[{"product_id":"2-extension-tube-for-1-25","title":"2\" Extension Tube for 1.25\"","description":"\u003cspan style=\"color: rgb(68, 68, 68); font-family: Arial, Helvetica, sans-serif; font-size: 14px; line-height: 20.299999237060547px; background-color: rgb(255, 255, 255);\"\u003eThe Antares Focus Extension 1.25\" extends the focal length of a 1.25\" focuser. Especially useful for use with an Auto Focuser where the focuser needs to be extended.\u003c\/span\u003e","brand":"Antares","offers":[{"title":"Default Title","offer_id":44012376457327,"sku":"ET1","price":23.76,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/et1__14747.jpg?v=1766547830"},{"product_id":"2-extension-tube-for-2","title":"2\" Extension Tube for 2\"","description":"\u003cp style=\"font-family: Verdana; font-size: 13.3333px; background-color: rgb(255, 255, 255);\"\u003eAntares 2 inch Extension Tubes for 2\" eyepieces or focusers, ET2\u003c\/p\u003e\u003cp style=\"font-family: Verdana; font-size: 13.3333px; background-color: rgb(255, 255, 255);\"\u003eProvides extra focuser travel which is usefull for short-range terrestrial viewing\u003c\/p\u003e\u003cp style=\"font-family: Verdana; font-size: 13.3333px; background-color: rgb(255, 255, 255);\"\u003eAnodized Black top and inside, polished machined aluminum tube adds 2 inches of extension\u003c\/p\u003e\u003cp style=\"font-family: Verdana; font-size: 13.3333px; background-color: rgb(255, 255, 255);\"\u003eTwo locking thumbscrews with a none maring brass band on the inside and threaded for filters. Fits 2\" eyepieces or focusers\u003c\/p\u003e","brand":"Antares","offers":[{"title":"Default Title","offer_id":44012381208687,"sku":"ET2","price":38.25,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/barrelexten125jpg__28574.jpg?v=1766547836"},{"product_id":"2-25-twist-lock-extension-tube-for-2","title":"2.25\" Twist Lock Extension Tube for 2\"","description":"\u003cspan style=\"color: rgb(68, 68, 68); font-family: Arial, Helvetica, sans-serif; font-size: 14px; line-height: 20.299999237060547px; background-color: rgb(255, 255, 255);\"\u003eThe Antares Extension Tube extends the length of any 2\" focuser. Useful with auto focusers. With twist lock.\u003c\/span\u003e","brand":"Antares","offers":[{"title":"Default Title","offer_id":44012381241455,"sku":"ET2TL","price":47.52,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/et2tl__17406.jpg?v=1766547840"},{"product_id":"1-75-twist-lock-extension-tube-for-2","title":"1.75\" Twist Lock Extension Tube for 2\"","description":"\u003cspan style=\"color: rgb(68, 68, 68); font-family: Arial, Helvetica, sans-serif; font-size: 14px; line-height: 20.299999237060547px; background-color: rgb(255, 255, 255);\"\u003eThe Antares Extension Tube extends the length of any 2\" focuser. Useful with auto focusers. With twist lock.\u003c\/span\u003e","brand":"Antares","offers":[{"title":"Default Title","offer_id":44012381274223,"sku":"ET1.5TL","price":47.52,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/et2tl__33857.jpg?v=1766547844"},{"product_id":"t-2-extension-tube-15mm-long","title":"T-2 Extension Tube (15mm long)","description":"\u003cspan style=\"color: rgb(50, 50, 50); font-family: Arial, Helvetica, sans-serif; font-size: 12px; background-color: rgb(255, 255, 255);\"\u003eT-2 Extension Tubes enable you to securely set or vary the spacing between T-2 components. This # T2-25A # 1508154 T-thread extension or spacer tube provides 15mm of extension. It features an internal T-2 thread (M42x0.75) at one end and an external T-2 thread at the opposite end. Full internal threading and blackening kills any stray light reflections. Maximum diameter = 47.5mm.\u003c\/span\u003e","brand":"Baader Planetarium","offers":[{"title":"Default Title","offer_id":44013396820079,"sku":"T2-25A","price":29.99,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/baader-t-2-15-mm-extension-tube-t-2-part-25a-d9f__32970.jpg?v=1766552758"},{"product_id":"m42-m42-extender-21mm-length","title":"M42-M42 extender (21mm length )","description":"\u003cspan style=\"font-family: Arial;\"\u003eZWO 21mm Extension ring.  M42 male and female threads.\u003c\/span\u003e","brand":"ZWO","offers":[{"title":"Default Title","offer_id":44013503807599,"sku":"ZWO-EXT-21","price":25.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/21mmExtend-1024x853__18315.jpg?v=1766554504"},{"product_id":"primaluce-lab-plus-20mm-spacers","title":"Primaluce Lab PLUS 20mm spacers","description":"\u003cspan style=\"font-family: Arial; font-size: 12pt; text-align: justify; background-color: rgb(255, 255, 255);\"\u003eWhen we install many instruments (for example telescope with guide scope in parallel) on the mount, it can happen that they are too close together, and that some element touches the others. That's why we created the PLUS 20mm spacers that can be fixed between two mechanical elements (such as a plate and the support rings), keeping the functionality of the PLUS system. In fact they have four holes, with 20mm separation to fix PLUS Vixen dovetail bars and guide rings and 55mm for PLUS Losmandy dovetail bars. The PLUS spacers have holes to fix the other elements always with M6 screws but of greater length (35mm) which are provided in the package (4 screws).\u003c\/span\u003e","brand":"Primaluce Lab","offers":[{"title":"Default Title","offer_id":44013591461999,"sku":"PLLSPES20","price":59.99,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/spessori-plus-spacers-20mm__80267.jpg?v=1766557208"},{"product_id":"primaluce-lab-plus-30mm-spacers","title":"Primaluce Lab PLUS 30mm spacers","description":"\u003cspan style=\"font-family: Arial; font-size: 12pt; text-align: justify; background-color: rgb(255, 255, 255);\"\u003eWhen we install many instruments (for example telescope with guide scope in parallel) on the mount, it can happen that they are too close together, and that some element touches the others. That's why we created the PLUS 20mm spacers that can be fixed between two mechanical elements (such as a plate and the support rings), keeping the functionality of the PLUS system. In fact they have four holes, with 20mm separation to fix PLUS Vixen dovetail bars and guide rings and 55mm for PLUS Losmandy dovetail bars. The PLUS spacers have holes to fix the other elements always with M6 screws but of greater length (35mm) which are provided in the package (4 screws).\u003c\/span\u003e","brand":"Primaluce Lab","offers":[{"title":"Default Title","offer_id":44013595623535,"sku":"PLLSPES30","price":66.99,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/spessori-plus-spacers-20mm__53092.jpg?v=1766557326"},{"product_id":"baader-varilock-46-variable-length-t-2-extension-tube-29-46mm","title":"Baader VariLock 46, Variable Length T-2 Extension tube 29-46mm","description":"\u003cdiv\u003e\u003cspan style=\"font-family: Arial;\"\u003eThe Baader VariLock T-2 Extension Tube gives you complete adjustability to enable you to exactly set or vary the spacing between T-2 components. The Varilock is the perfect thing for adjusting your back-focus when introducing a focal reducer, field flattener or any other optical or imaging system components. Full internal threading and blackening kills any stray light reflections. 2\" OD enables use in any 2\" system.\u003c\/span\u003e\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;\"\u003eThe Baader VariLock extension tubes feature an accurately engraved graduated scale, shown in 0.5 mm gradations, for an easy visual determination of the tube length. Simply rotate the inner tube until the desired length is reached, then tighten the lockring with the included spanner wrench. The connection is very sturdy, and you'll be so happy with the length adjustability factor! The Varilock 46 variable extension tube can be set to as short as 29mm to as long as 46mm. If you need a shorter variable extension tube, take a look at the Baader Varilock 29 (T2-25Y), with a range of 20mm to 29mm.\u003c\/span\u003e\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;\"\u003eThe Varilock 46 is also perfectly suited for setting the correct spacing of the Baader RCC-I coma corrector onto DSLRs (when adjusted to 36.5mm). As an added bonus, if you wish to image through a DSLR, the external T-threaded portion can be removed and replaced with an included dovetail ring, allowing you to attach a t-ring matching your camera's mounting system.\u003c\/span\u003e\u003c\/div\u003e","brand":"Baader Planetarium","offers":[{"title":"Default Title","offer_id":44013658177647,"sku":"T2-25V","price":99.99,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/bad-t2-25v-2__55002.jpg?v=1766558918"},{"product_id":"baader-t-2-adjustment-spacer-rings","title":"Baader T-2 adjustment\/spacer-rings","description":"\u003cul style=\"box-sizing: inherit; -webkit-font-smoothing: antialiased; text-size-adjust: none; -webkit-tap-highlight-color: rgba(0, 0, 0, 0); margin-top: 0.9375rem; margin-bottom: 0.9375rem; color: rgb(76, 81, 84); font-family: \" libre franklin sans-serif font-size:=\"\" padding:=\"\" margin-left:=\"\"\u003e\n\u003cli style=\"box-sizing: inherit; -webkit-font-smoothing: antialiased; text-size-adjust: none; -webkit-tap-highlight-color: rgba(0, 0, 0, 0); list-style: disc !important;\"\u003eAltogether 15 pc - in 5 sizes, three rings per size (thickness 0.6\/0.8\/1.0\/1.2\/1.4mm)\u003c\/li\u003e\n\u003cli style=\"box-sizing: inherit; -webkit-font-smoothing: antialiased; text-size-adjust: none; -webkit-tap-highlight-color: rgba(0, 0, 0, 0); list-style: disc !important;\"\u003eWell suited to tune the rotary position of all kinds of T-2 accessories in approx 90° increments, to move locking screws of eyepiece holders into a comfortable position asf.\u003c\/li\u003e\n\u003cli style=\"box-sizing: inherit; -webkit-font-smoothing: antialiased; text-size-adjust: none; -webkit-tap-highlight-color: rgba(0, 0, 0, 0); list-style: disc !important;\"\u003eAlso helps to prevent binding when used as spacer between two metal surfaces connected w. T-2 thread\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Baader Planetarium","offers":[{"title":"Default Title","offer_id":44013742325871,"sku":"T2RING","price":24.99,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/2458102-8-O-N-1_799x532__71743.jpg?v=1766561417"},{"product_id":"m68-extension-tube-10mm-long","title":"M68 Extension Tube, 10mm Long","description":"M68 Extension Tube, 10mm Long","brand":"Ontario Telescope and Accessories","offers":[{"title":"Default Title","offer_id":44013754482799,"sku":"M68\/10","price":60.0,"currency_code":"CAD","in_stock":true}]},{"product_id":"m68-extension-tube-60mm-long","title":"M68 Extension Tube, 60mm Long","description":"M68 Extension Tube, 60mm Long","brand":"Ontario Telescope and Accessories","offers":[{"title":"Default Title","offer_id":44013754613871,"sku":"M68\/60","price":100.0,"currency_code":"CAD","in_stock":true}]},{"product_id":"starchaser-spacers","title":"StarChaser Spacers","description":"\u003cp\u003eWe have a variety of spacers available to customize the back focus distance of your StarChaser camera.  Mount these between your StarChaser and the camera or filter wheel.  \u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eCurrent options include:\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e3″ diameter 0.75″ (19 mm) thick spacer for SC-3 series\u003c\/li\u003e\n\u003cli\u003e3″ diameter 0.55″ (14 mm) thick spacer for SC-3 series (same thickness as standard AFW series filter wheels)\u003c\/li\u003e\n\u003cli\u003e2″ diameter 0.15″ (4 mm) thick spacer for SC-2 series\u003c\/li\u003e\n\u003cli\u003e2″ diameter 0.45″ (11.5 mm) thick spacer for SC-2 series.  Recommended when mounting an SC-2 to an STC-7.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eEach spacer comes with longer mounting screws for use with your StarChaser off-axis guide camera.\u003c\/p\u003e","brand":"Diffraction Limited","offers":[{"title":"3\" DIAMETER 0.75\" (SC-3 SERIES)","offer_id":44013963968623,"sku":"ACC15","price":268.65,"currency_code":"CAD","in_stock":true},{"title":"3\" DIAMETER 0.55\" (SC-3 SERIES)","offer_id":44013964001391,"sku":"ACC15","price":268.65,"currency_code":"CAD","in_stock":true},{"title":"2\" DIAMETER 0.15\" (SC-2 SERIES)","offer_id":44013964034159,"sku":"ACC15","price":268.65,"currency_code":"CAD","in_stock":true},{"title":"2\" DIAMETER 0.75\" (SC-2 SERIES)","offer_id":44013964066927,"sku":"ACC15","price":268.65,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/Adapter__74470.jpg?v=1766567252"},{"product_id":"askar-m54-m48-backfocus-adjuster","title":"Askar M54\/M48 Backfocus Adjuster","description":"\u003ch2\u003eProduct Overview\u003c\/h2\u003e\u003cp\u003eThe Askar M54\/M48 Backfocus Adjuster is an astronomy imaging accessory used to fine-tune camera spacing in an optical train. It is intended for astrophotography setups where precise backfocus adjustment is required between a telescope, reducer, flattener, filter drawer, OAG, or camera.\u003c\/p\u003e\u003ch2\u003eWho Is This Product Best For?\u003c\/h2\u003e\u003cp\u003eThis accessory is best for astrophotographers who need small spacing adjustments to dial in field correction, improve star shapes, or match the required camera-side backfocus for their imaging system.\u003c\/p\u003e\u003ch2\u003eWhy Choose This Product?\u003c\/h2\u003e\u003cul\u003e\n\u003cli\u003eUseful for fine backfocus adjustment in imaging trains.\u003c\/li\u003e\n\u003cli\u003eSupports M54\/M48-style astronomy connections.\u003c\/li\u003e\n\u003cli\u003eHelps tune camera spacing for reducers, flatteners, and correctors.\u003c\/li\u003e\n\u003cli\u003eCompact accessory for deep-sky astrophotography setups.\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch2\u003eRecommended Uses\u003c\/h2\u003e\u003cul\u003e\n\u003cli\u003eBackfocus adjustment for cooled astronomy cameras.\u003c\/li\u003e\n\u003cli\u003eSpacing correction with reducers and flatteners.\u003c\/li\u003e\n\u003cli\u003eImaging-train tuning for better corner star performance.\u003c\/li\u003e\n\u003cli\u003eAccessory spacing in M54\/M48 optical systems.\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch2\u003eCompatibility and Accessory Notes\u003c\/h2\u003e\u003cp\u003eConfirm thread compatibility, required spacing, and available mechanical clearance before use. This draft uses placeholder pricing and should be reviewed manually before publishing.\u003c\/p\u003e\u003ch2\u003eImportant Limitations\u003c\/h2\u003e\u003cul\u003e\n\u003cli\u003eThis is an adapter\/accessory only; it is not an optical telescope or camera.\u003c\/li\u003e\n\u003cli\u003eExact compatibility depends on the user's telescope, reducer\/flattener, filter drawer, OAG, and camera setup.\u003c\/li\u003e\n\u003cli\u003ePricing is set to $0.00 as a manual placeholder.\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch2\u003eOur Recommendation\u003c\/h2\u003e\u003cp\u003eOntario Telescope recommends this accessory for imagers who need to fine-tune backfocus spacing in an M54\/M48 imaging train.\u003c\/p\u003e","brand":"Askar","offers":[{"title":"Default Title","offer_id":53155943121007,"sku":"ASK-M54-M48-BACKFOCUS","price":198.99,"currency_code":"CAD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/backfocusadjuster1.webp?v=1779736411"},{"product_id":"player-one-1-25-extender-20mm-m28-5","title":"Player One 1.25\" Extender (20mm, M28.5)","description":"\u003ch3\u003e\u003cstrong\u003eProduct Overview\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eThe Player One 1.25\" Extender is a machined metal spacer that adds a fixed 20 mm of optical-train length between 1.25-inch threaded components. It carries M28.5 × 0.6 female threads on one end and M28.5 × 0.6 male threads on the other, so it threads in line without changing the thread standard. It was designed for use with guide cameras and other M28.5 (1.25-inch) threaded accessories, where a small amount of extra spacing is needed to reach focus or clear a filter.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eWho It's For\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eThis is a good match if you are building a 1.25-inch guiding or imaging train and need to add length between two M28.5-threaded parts — for example, spacing a guide camera back from a filter or nosepiece so the assembly reaches focus.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eKey Features \u0026amp; Design\u003c\/strong\u003e\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eFixed 20 mm spacing:\u003c\/strong\u003e adds 20 mm of length (plus 2.5 mm of engaged thread) in a single component.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eM28.5 × 0.6 threads:\u003c\/strong\u003e female one end, male the other — the standard 1.25-inch filter\/accessory thread.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMetal construction:\u003c\/strong\u003e machined metal body for a rigid, repeatable join.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMechanical only:\u003c\/strong\u003e no optical elements and no electronic connection.\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003e\u003cstrong\u003eRecommended Uses\u003c\/strong\u003e\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eGuide-camera spacing:\u003c\/strong\u003e extend a guide camera back from a filter, nosepiece, or off-axis guider port.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e1.25-inch train building:\u003c\/strong\u003e add a known 20 mm step when a threaded 1.25-inch assembly needs to reach focus.\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003e\u003cstrong\u003eCompatibility \u0026amp; Accessory Notes\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eBoth ends use the M28.5 × 0.6 thread standard common to 1.25-inch filters and accessories — female on one side, male on the other. It passes the 1.25-inch thread straight through and does not adapt to any other standard. If you are not sure how much spacing your train needs, send us your camera and accessory setup and we will work it out with you.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eGood to Know Before You Order\u003c\/strong\u003e\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eMechanical adapter only:\u003c\/strong\u003e it adds length and carries the thread — there are no optics and no electronic communication through it.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFixed length:\u003c\/strong\u003e the 20 mm step is not adjustable.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eThread standard:\u003c\/strong\u003e both ends are M28.5 × 0.6; it does not convert 1.25-inch to any other thread.\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003e\u003cstrong\u003eFrequently Asked Questions\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eIs it difficult to set up?\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003eNo — it threads directly in line between two M28.5 components and needs no tools or adjustment.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow much length does it add?\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003e20 mm, plus 2.5 mm of engaged thread.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eDoes it change the thread size?\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003eNo. Both ends are M28.5 × 0.6, so it keeps the 1.25-inch thread standard on both sides.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eDoes it have any optics?\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003eNo. It is a mechanical spacer with no optical elements and no electronic connection.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eBottom Line\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eIn short: a machined metal 20 mm spacer with M28.5 × 0.6 threads on both ends, made to add a known step of length inside a 1.25-inch guiding or imaging train.\u003c\/p\u003e","brand":"Player One Astronomy","offers":[{"title":"Default Title","offer_id":53834272604271,"sku":"125EXT","price":16.8,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/1.25-EXTENDER-1024x1024.jpg?v=1784239493"},{"product_id":"player-one-m42f-m42m-20mm-extender","title":"Player One M42F-M42M 20mm Extender","description":"\u003ch3\u003e\u003cstrong\u003eProduct Overview\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eThe Player One M42F-M42M 20mm Extender is a machined aluminium spacer that adds 20 mm of length between M42 × 0.75 (T-thread) components. It carries M42 × 0.75 female threads on one end and M42 × 0.75 male threads on the other, so it threads in line without changing the thread standard. It is used to build up spacing in an M42 imaging train — typically to reach a required backfocus distance.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eWho It's For\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eThis is a good match if you are assembling an M42-threaded imaging train and need a known 20 mm step to reach the backfocus your camera, filter drawer, or corrector calls for.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eKey Features \u0026amp; Design\u003c\/strong\u003e\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eFixed 20 mm spacing:\u003c\/strong\u003e adds a precise 20 mm of length in a single component.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eM42 × 0.75 threads:\u003c\/strong\u003e female one end, male the other — the common T-thread \/ M42 standard.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAluminium 6061-T6:\u003c\/strong\u003e machined aluminium body, light and rigid.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMechanical only:\u003c\/strong\u003e no optical elements and no electronic connection.\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003e\u003cstrong\u003eRecommended Uses\u003c\/strong\u003e\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eBackfocus spacing:\u003c\/strong\u003e add 20 mm toward a corrector, flattener, or camera backfocus figure.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eM42 train building:\u003c\/strong\u003e insert a known step between M42-threaded parts.\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003e\u003cstrong\u003eCompatibility \u0026amp; Accessory Notes\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eBoth ends use the M42 × 0.75 thread standard — female on one side, male on the other. It passes the M42 thread straight through and does not convert to another standard. Backfocus is a sum of every part in the train; if you are working out how much spacing you need, send us your camera, filter, and corrector setup and we will work it out with you.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eGood to Know Before You Order\u003c\/strong\u003e\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eMechanical adapter only:\u003c\/strong\u003e it adds length and carries the thread — there are no optics and no electronic communication through it.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFixed length:\u003c\/strong\u003e the 20 mm step is not adjustable.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eThread standard:\u003c\/strong\u003e both ends are M42 × 0.75; it does not convert M42 to any other thread.\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003e\u003cstrong\u003eFrequently Asked Questions\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eIs it difficult to set up?\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003eNo — it threads directly in line between two M42 components and needs no tools or adjustment.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow much length does it add?\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003e20 mm.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eDoes it change the thread size?\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003eNo. Both ends are M42 × 0.75, so it keeps the M42 (T-thread) standard on both sides.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eDoes it have any optics?\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003eNo. It is a mechanical spacer with no optical elements and no electronic connection.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eBottom Line\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eIn short: a machined aluminium 20 mm spacer with M42 × 0.75 threads on both ends, made to set a known step of backfocus in an M42 imaging train.\u003c\/p\u003e","brand":"Player One Astronomy","offers":[{"title":"Default Title","offer_id":53834275815535,"sku":"M42F-M42M-20","price":33.6,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/M42F-M42M-20mm-Extender2-1024x575.png?v=1784239621"},{"product_id":"player-one-m54m-m54f-17-5mm-extender","title":"Player One M54M-M54F 17.5mm Extender","description":"\u003ch3\u003e\u003cstrong\u003eOverview\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eThe Player One M54M-M54F 17.5mm Extender is a machined spacer with an M54×0.75 male thread on one end and an M54×0.75 female thread on the other, adding 17.5 mm to the optical path. It is a purely mechanical part with no glass and no electronics, made from aluminum 6061-T6.\u003c\/p\u003e\n\u003ch3\u003e\u003cstrong\u003eWho It's For\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eThis is a good match if you are building an M54 imaging train and need 17.5 mm of extra length to reach a target backfocus while keeping the M54 thread on both sides.\u003c\/p\u003e\n\u003ch3\u003e\u003cstrong\u003eKey Features \u0026amp; Design\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eM54 male to M54 female:\u003c\/strong\u003e M54×0.75 male on one end, M54×0.75 female on the other, so it stacks in line.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e17.5 mm spacing:\u003c\/strong\u003e adds a fixed 17.5 mm to the optical path.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAluminum 6061-T6 body:\u003c\/strong\u003e light, corrosion-resistant, and dimensionally stable.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFully mechanical:\u003c\/strong\u003e no optical elements and no electrical connection.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003e\u003cstrong\u003eRecommended Uses\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eUse it to add 17.5 mm of spacing within an M54 imaging train — for example between a camera, filter wheel, or off-axis guider and the rest of the train — to hit a required backfocus.\u003c\/p\u003e\n\u003ch3\u003e\u003cstrong\u003eCompatibility \u0026amp; Accessory Notes\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eThe extender fits standard M54×0.75 threads. Because it is a fixed-length spacer, include its 17.5 mm in your total backfocus calculation. If you are not sure how much spacing your imaging train needs, send us your camera, filter, and corrector setup and we will work out the numbers with you.\u003c\/p\u003e\n\u003ch3\u003e\u003cstrong\u003eGood to Know Before You Order\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eMechanical spacer only:\u003c\/strong\u003e it carries no optical elements and passes no electronic signal.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFixed 17.5 mm length:\u003c\/strong\u003e the spacing it adds is set and not adjustable.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eM54 in, M54 out:\u003c\/strong\u003e it keeps the M54 thread standard on both sides rather than converting it.\u003c\/li\u003e\n\u003c\/ul\u003e\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 — it threads directly into an M54 train by hand and needs no tools or adjustment.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWhat is it best used for?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eAdding a fixed 17.5 mm of spacing to reach a target backfocus in an M54 imaging train.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eDoes it contain any optics?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eNo. It is a bare mechanical spacer with no lenses or coatings.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eHow much backfocus does it add?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003e17.5 mm, which you should include in your spacing total.\u003c\/p\u003e\n\u003ch3\u003e\u003cstrong\u003eBottom Line\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eIn short: a machined aluminum M54 male-to-female spacer that adds a fixed 17.5 mm to the optical path, for dialing in backfocus within an M54 imaging train.\u003c\/p\u003e","brand":"Player One Astronomy","offers":[{"title":"Default Title","offer_id":53834292527215,"sku":"M54M-M54F-17.5","price":49.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/M54F-M54M-17.5mm-extender-2.jpg?v=1784239741"},{"product_id":"player-one-m48f-m42m-17-5mm-extender","title":"Player One M48F-M42M 17.5mm Extender","description":"\u003ch3\u003e\u003cstrong\u003eProduct Overview\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eThe Player One M48F-M42M 17.5mm Extender is a machined aluminium spacer that adds 17.5 mm of length while converting between thread standards. It carries M48 × 0.75 female threads on one end and M42 × 0.75 male threads on the other, so it both extends the train and steps M48 down to M42. It is used to reach a required backfocus while changing to the M42 (T-thread) interface.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eWho It's For\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eThis is a good match if your train needs both an M48-to-M42 step and about 17.5 mm of added length — for example, taking an M48 output down to an M42 camera or filter drawer at the right backfocus.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eKey Features \u0026amp; Design\u003c\/strong\u003e\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003e17.5 mm spacing:\u003c\/strong\u003e adds a precise 17.5 mm of length.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eM48 female to M42 male:\u003c\/strong\u003e steps M48 × 0.75 down to M42 × 0.75 in the same part.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAluminium 6061-T6:\u003c\/strong\u003e machined aluminium body, light and rigid.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMechanical only:\u003c\/strong\u003e no optical elements and no electronic connection.\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003e\u003cstrong\u003eRecommended Uses\u003c\/strong\u003e\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eBackfocus spacing:\u003c\/strong\u003e add 17.5 mm toward a camera, filter, or corrector backfocus figure.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eM48-to-M42 step:\u003c\/strong\u003e convert an M48 interface to M42 while adding length.\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003e\u003cstrong\u003eCompatibility \u0026amp; Accessory Notes\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eOne end is M48 × 0.75 female; the other is M42 × 0.75 male. It both extends the train and converts M48 to M42. Backfocus is a sum of every part in the train; if you are working out how much spacing you need, send us your camera, filter, and corrector setup and we will work it out with you.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eGood to Know Before You Order\u003c\/strong\u003e\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eMechanical adapter only:\u003c\/strong\u003e it adds length and steps the thread — there are no optics and no electronic communication through it.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFixed length:\u003c\/strong\u003e the 17.5 mm step is not adjustable.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eThread step:\u003c\/strong\u003e M48 × 0.75 female to M42 × 0.75 male.\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003e\u003cstrong\u003eFrequently Asked Questions\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eIs it difficult to set up?\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003eNo — it threads directly between an M48 female part and an M42 male part with no tools or adjustment.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow much length does it add?\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003e17.5 mm.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eDoes it change the thread size?\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003eYes. It steps M48 × 0.75 female down to M42 × 0.75 male.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eBottom Line\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eIn short: a machined aluminium 17.5 mm extender that steps M48 down to M42, for setting backfocus while changing to the M42 interface.\u003c\/p\u003e","brand":"Player One Astronomy","offers":[{"title":"Default Title","offer_id":53834292592751,"sku":"M48F-M42M-17.5","price":33.6,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/M48F-M42M-17.5mm-Extender-logo.png?v=1784239742"},{"product_id":"player-one-m54m-m54f-20mm-extender","title":"Player One M54M-M54F 20mm Extender","description":"\u003ch3\u003e\u003cstrong\u003eOverview\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eThe Player One M54M-M54F 20mm Extender is a machined spacer with an M54×0.75 male thread on one end and an M54×0.75 female thread on the other, adding 20 mm to the optical path. It is a purely mechanical part with no glass and no electronics, made from aluminum 6061-T6.\u003c\/p\u003e\n\u003ch3\u003e\u003cstrong\u003eWho It's For\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eThis is a good match if you are building an M54 imaging train and need 20 mm of extra length to reach a target backfocus while keeping the M54 thread on both sides.\u003c\/p\u003e\n\u003ch3\u003e\u003cstrong\u003eKey Features \u0026amp; Design\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eM54 male to M54 female:\u003c\/strong\u003e M54×0.75 male on one end, M54×0.75 female on the other, so it stacks in line.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e20 mm spacing:\u003c\/strong\u003e adds a fixed 20 mm to the optical path.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAluminum 6061-T6 body:\u003c\/strong\u003e light, corrosion-resistant, and dimensionally stable.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFully mechanical:\u003c\/strong\u003e no optical elements and no electrical connection.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003e\u003cstrong\u003eRecommended Uses\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eUse it to add 20 mm of spacing within an M54 imaging train — for example between a camera, filter wheel, or off-axis guider and the rest of the train — to hit a required backfocus.\u003c\/p\u003e\n\u003ch3\u003e\u003cstrong\u003eCompatibility \u0026amp; Accessory Notes\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eThe extender fits standard M54×0.75 threads. Because it is a fixed-length spacer, include its 20 mm in your total backfocus calculation. If you are not sure how much spacing your imaging train needs, send us your camera, filter, and corrector setup and we will work out the numbers with you.\u003c\/p\u003e\n\u003ch3\u003e\u003cstrong\u003eGood to Know Before You Order\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eMechanical spacer only:\u003c\/strong\u003e it carries no optical elements and passes no electronic signal.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFixed 20 mm length:\u003c\/strong\u003e the spacing it adds is set and not adjustable.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eM54 in, M54 out:\u003c\/strong\u003e it keeps the M54 thread standard on both sides rather than converting it.\u003c\/li\u003e\n\u003c\/ul\u003e\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 — it threads directly into an M54 train by hand and needs no tools or adjustment.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWhat is it best used for?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eAdding a fixed 20 mm of spacing to reach a target backfocus in an M54 imaging train.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eDoes it contain any optics?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eNo. It is a bare mechanical spacer with no lenses or coatings.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eHow much backfocus does it add?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003e20 mm, which you should include in your spacing total.\u003c\/p\u003e\n\u003ch3\u003e\u003cstrong\u003eBottom Line\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eIn short: a machined aluminum M54 male-to-female spacer that adds a fixed 20 mm to the optical path, for dialing in backfocus within an M54 imaging train.\u003c\/p\u003e","brand":"Player One Astronomy","offers":[{"title":"Default Title","offer_id":53834293182575,"sku":"M54M-M54F-20","price":49.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/M54F-M54M-20mm-extender-2.jpg?v=1784239759"},{"product_id":"player-one-m48f-m48m-17-5mm-extender","title":"Player One M48F-M48M 17.5mm Extender","description":"\u003ch3\u003e\u003cstrong\u003eProduct Overview\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eThe Player One M48F-M48M 17.5mm Extender is a machined aluminium spacer that adds 17.5 mm of length between M48 × 0.75 components. It carries M48 × 0.75 female threads on one end and M48 × 0.75 male threads on the other, so it threads in line without changing the thread standard. It is used to build up spacing in an M48 imaging train to reach a required backfocus distance.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eWho It's For\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eThis is a good match if you are assembling an M48-threaded imaging train and need a known 17.5 mm step to reach the backfocus your camera, filter drawer, or corrector calls for.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eKey Features \u0026amp; Design\u003c\/strong\u003e\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eFixed 17.5 mm spacing:\u003c\/strong\u003e adds a precise 17.5 mm of length in a single component.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eM48 × 0.75 threads:\u003c\/strong\u003e female one end, male the other — the common large-format M48 standard.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAluminium 6061-T6:\u003c\/strong\u003e machined aluminium body, light and rigid.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMechanical only:\u003c\/strong\u003e no optical elements and no electronic connection.\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003e\u003cstrong\u003eRecommended Uses\u003c\/strong\u003e\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eBackfocus spacing:\u003c\/strong\u003e add 17.5 mm toward a corrector, flattener, or camera backfocus figure.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eM48 train building:\u003c\/strong\u003e insert a known step between M48-threaded parts.\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003e\u003cstrong\u003eCompatibility \u0026amp; Accessory Notes\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eBoth ends use the M48 × 0.75 thread standard — female on one side, male on the other. It passes the M48 thread straight through and does not convert to another standard. Backfocus is a sum of every part in the train; if you are working out how much spacing you need, send us your camera, filter, and corrector setup and we will work it out with you.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eGood to Know Before You Order\u003c\/strong\u003e\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eMechanical adapter only:\u003c\/strong\u003e it adds length and carries the thread — there are no optics and no electronic communication through it.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFixed length:\u003c\/strong\u003e the 17.5 mm step is not adjustable.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eThread standard:\u003c\/strong\u003e both ends are M48 × 0.75; it does not convert M48 to any other thread.\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003e\u003cstrong\u003eFrequently Asked Questions\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eIs it difficult to set up?\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003eNo — it threads directly in line between two M48 components and needs no tools or adjustment.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow much length does it add?\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003e17.5 mm.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eDoes it change the thread size?\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003eNo. Both ends are M48 × 0.75, so it keeps the M48 standard on both sides.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eBottom Line\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eIn short: a machined aluminium 17.5 mm spacer with M48 × 0.75 threads on both ends, made to set a known step of backfocus in an M48 imaging train.\u003c\/p\u003e","brand":"Player One Astronomy","offers":[{"title":"Default Title","offer_id":53834293248111,"sku":"M48F-M48M-17.5","price":33.6,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/M48F-M48M-17.5mm-Extender-s.png?v=1784239767"},{"product_id":"player-one-m48f-m48m-20mm-extender","title":"Player One M48F-M48M 20mm Extender","description":"\u003ch3\u003e\u003cstrong\u003eProduct Overview\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eThe Player One M48F-M48M 20mm Extender is a machined aluminium spacer that adds 20 mm of length between M48 × 0.75 components. It carries M48 × 0.75 female threads on one end and M48 × 0.75 male threads on the other, so it threads in line without changing the thread standard. It is used to build up spacing in an M48 imaging train to reach a required backfocus distance.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eWho It's For\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eThis is a good match if you are assembling an M48-threaded imaging train and need a known 20 mm step to reach the backfocus your camera, filter drawer, or corrector calls for.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eKey Features \u0026amp; Design\u003c\/strong\u003e\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eFixed 20 mm spacing:\u003c\/strong\u003e adds a precise 20 mm of length in a single component.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eM48 × 0.75 threads:\u003c\/strong\u003e female one end, male the other — the common large-format M48 standard.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAluminium 6061-T6:\u003c\/strong\u003e machined aluminium body, light and rigid.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMechanical only:\u003c\/strong\u003e no optical elements and no electronic connection.\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003e\u003cstrong\u003eRecommended Uses\u003c\/strong\u003e\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eBackfocus spacing:\u003c\/strong\u003e add 20 mm toward a corrector, flattener, or camera backfocus figure.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eM48 train building:\u003c\/strong\u003e insert a known step between M48-threaded parts.\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003e\u003cstrong\u003eCompatibility \u0026amp; Accessory Notes\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eBoth ends use the M48 × 0.75 thread standard — female on one side, male on the other. It passes the M48 thread straight through and does not convert to another standard. Backfocus is a sum of every part in the train; if you are working out how much spacing you need, send us your camera, filter, and corrector setup and we will work it out with you.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eGood to Know Before You Order\u003c\/strong\u003e\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eMechanical adapter only:\u003c\/strong\u003e it adds length and carries the thread — there are no optics and no electronic communication through it.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFixed length:\u003c\/strong\u003e the 20 mm step is not adjustable.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eThread standard:\u003c\/strong\u003e both ends are M48 × 0.75; it does not convert M48 to any other thread.\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003e\u003cstrong\u003eFrequently Asked Questions\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eIs it difficult to set up?\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003eNo — it threads directly in line between two M48 components and needs no tools or adjustment.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow much length does it add?\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003e20 mm.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eDoes it change the thread size?\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003eNo. Both ends are M48 × 0.75, so it keeps the M48 standard on both sides.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eBottom Line\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eIn short: a machined aluminium 20 mm spacer with M48 × 0.75 threads on both ends, made to set a known step of backfocus in an M48 imaging train.\u003c\/p\u003e","brand":"Player One Astronomy","offers":[{"title":"Default Title","offer_id":53834293346415,"sku":"M48F-M48M-20","price":33.6,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/M48F-M48M-20mm-Extender-s.png?v=1784239791"},{"product_id":"player-one-m54m-m68f-17-5mm-extender","title":"Player One M54M-M68F 17.5mm Extender","description":"\u003ch3\u003e\u003cstrong\u003eOverview\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eThe Player One M54M-M68F 17.5mm Extender is a machined spacer with an M54×0.75 male thread on one end and an M68 female thread on the other, adding 17.5 mm to the optical path. It is a purely mechanical part with no glass and no electronics, made from aluminum 6061-T6.\u003c\/p\u003e\n\u003ch3\u003e\u003cstrong\u003eWho It's For\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eThis is a good match if you are bridging an M54 section of an imaging train to an M68 interface — such as a large flattener or telescope rear thread — and need 17.5 mm of length to reach a target backfocus.\u003c\/p\u003e\n\u003ch3\u003e\u003cstrong\u003eKey Features \u0026amp; Design\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eM54 male to M68 female:\u003c\/strong\u003e M54×0.75 male on one end, M68 female on the other.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e17.5 mm spacing:\u003c\/strong\u003e adds a fixed 17.5 mm to the optical path.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAluminum 6061-T6 body:\u003c\/strong\u003e light, corrosion-resistant, and dimensionally stable.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFully mechanical:\u003c\/strong\u003e no optical elements and no electrical connection.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003e\u003cstrong\u003eRecommended Uses\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eUse it to step an M54 imaging train up to an M68 interface while adding 17.5 mm of spacing, for example between a camera-side M54 train and an M68 flattener or telescope adapter.\u003c\/p\u003e\n\u003ch3\u003e\u003cstrong\u003eCompatibility \u0026amp; Accessory Notes\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eThe extender presents an M54×0.75 male thread on one side and an M68 female thread on the other. Because it is a fixed-length spacer, include its 17.5 mm in your total backfocus calculation. If you want to confirm the M68 thread matches your flattener or telescope, send us the model and we will check it with you.\u003c\/p\u003e\n\u003ch3\u003e\u003cstrong\u003eGood to Know Before You Order\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eMechanical spacer only:\u003c\/strong\u003e it carries no optical elements and passes no electronic signal.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFixed 17.5 mm length:\u003c\/strong\u003e the spacing it adds is set and not adjustable.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eThread conversion:\u003c\/strong\u003e it converts M54 male to M68 female, so both mating parts need the matching threads.\u003c\/li\u003e\n\u003c\/ul\u003e\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 — it threads into an M54 male and an M68 female interface by hand and needs no tools or adjustment.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWhat is it best used for?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eBridging an M54 imaging train to an M68 interface while adding a fixed 17.5 mm of spacing.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eDoes it contain any optics?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eNo. It is a bare mechanical spacer with no lenses or coatings.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eHow much backfocus does it add?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003e17.5 mm, which you should include in your spacing total.\u003c\/p\u003e\n\u003ch3\u003e\u003cstrong\u003eBottom Line\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eIn short: a machined aluminum M54 male to M68 female spacer that adds a fixed 17.5 mm to the optical path, for bridging M54 and M68 sections of an imaging train.\u003c\/p\u003e","brand":"Player One Astronomy","offers":[{"title":"Default Title","offer_id":53834293444719,"sku":"M54M-M68F-17.5","price":54.6,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/M68F-M54M-20mm-extender-2.jpg?v=1784239803"},{"product_id":"takahashi-fs-60cb-auxiliary-ring-57mm","title":"Takahashi FS-60CB Auxiliary Ring 57mm","description":"\u003ch3\u003e\u003cstrong\u003eProduct Overview\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eThe Auxiliary Ring (FS-60CB) is a Takahashi adapter ring built for the FS-60CB refractor's camera-side thread. It carries a published light path of 57 mm — the amount it adds to your optical train, not its physical length end to end — with an M52 x 0.75 male thread on one side and an M55.9 x 0.75 female thread on the other.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eWho It's For\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eThis is a good match if you own an FS-60CB and need to extend or adapt its camera-side connection to reach a specific back focus or fit an additional accessory in the train.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eKey Features \u0026amp; Design\u003c\/strong\u003e\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003e57 mm published light path:\u003c\/strong\u003e a fixed, known contribution to your back focus total.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eM52 x 0.75 male to M55.9 x 0.75 female threads:\u003c\/strong\u003e matches the FS-60CB's own camera-side interface on one end.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSingle-piece aluminum ring:\u003c\/strong\u003e no moving parts to maintain.\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003e\u003cstrong\u003eRecommended Uses\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eExtending the FS-60CB's camera-side train for imaging, or adapting it to accept a further eyepiece or coupling for visual use.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eCompatibility and Accessory Notes\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eBuilt for the FS-60CB. Because 57 mm is a meaningful fraction of most imaging back-focus budgets, it is worth checking this figure against your camera and any flattener or reducer already in the train — the \u003ca href=\"\/pages\/takahashi-back-focus-guide\"\u003eTakahashi Back Focus Guide\u003c\/a\u003e tabulates every Takahashi adapter's light path alongside each telescope's back focus target.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eGood to Know Before You Order\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eLight path adds up quickly on a short-focus scope:\u003c\/strong\u003e on the FS-60CB, 57 mm is a large share of the available back focus budget. Send us your full camera and accessory chain and we will work out the total spacing with you.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eFrequently Asked Questions\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eIs it difficult to set up?\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003eNo — it threads on at both ends with no adjustment involved.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat is it used for?\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003eAdding a defined 57 mm of light path to the FS-60CB's camera-side train, most often to reach a target back focus for a flattener or camera.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eDoes it change what the FS-60CB can be used for?\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003eNo — it is a mechanical spacer with no optical elements, so it works the same for visual or imaging use.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eBottom Line\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eA 57 mm light-path ring for the FS-60CB, with M52 male and M55.9 female threads on either end. It is worth confirming against the rest of your train before ordering.\u003c\/p\u003e","brand":"Takahashi","offers":[{"title":"Default Title","offer_id":54047908266095,"sku":"TAK-TKP20001","price":102.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/tkp20001.jpg?v=1786936369"},{"product_id":"takahashi-cca-250-98mm-spacer-ring-32-5mm","title":"Takahashi CCA-250 98mm Spacer Ring 32.5mm","description":"\u003ch3\u003e\u003cstrong\u003eProduct Overview\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eThe 98mm Spacer Ring is a Takahashi M98 x 1.0 extension built for the CCA-250, most often paired with the TKA86580L super reducer. Takahashi publishes a 32.5 mm light path for it — the amount it contributes to your optical train, not its physical length end to end.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eWho It's For\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eThis is a good match if you run a CCA-250 with the TKA86580L super reducer and need to add 32.5 mm of spacing to reach your target back focus.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eKey Features \u0026amp; Design\u003c\/strong\u003e\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eM98 x 1.0 thread:\u003c\/strong\u003e matches the CCA-250 and Mewlon CRS body accessory family.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e32.5 mm published light path:\u003c\/strong\u003e a fixed, known contribution to your back focus total.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eConnects through to the camera rotator:\u003c\/strong\u003e pairs with the TKP86003 adapter for rotator attachment.\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003e\u003cstrong\u003eRecommended Uses\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eAdding spacing in a CCA-250 imaging train that uses the TKA86580L super reducer, ahead of the camera rotator.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eCompatibility and Accessory Notes\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eBuilt for the CCA-250 with the TKA86580L super reducer, and connects to the camera rotator via the TKP86003 adapter. The 32.5 mm figure is worth adding to your full back-focus total alongside the reducer and camera — the \u003ca href=\"\/pages\/takahashi-back-focus-guide\"\u003eTakahashi Back Focus Guide\u003c\/a\u003e tabulates every Takahashi adapter's light path alongside each telescope's back focus target.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eGood to Know Before You Order\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eIt is a fixed-length spacer, not adjustable:\u003c\/strong\u003e if 32.5 mm does not land your train at the CCA-250's reducer back-focus target, a different-length ring is the fix rather than trimming this one. Send us your full CCA-250 imaging chain and we will work out the right combination with you.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eFrequently Asked Questions\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eIs it difficult to set up?\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003eNo — it threads in between the reducer and rotator adapter with no adjustment involved.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat is it used for?\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003eAdding a fixed 32.5 mm of spacing in a CCA-250 imaging train built around the TKA86580L super reducer.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eDoes it work with the CCA-250's visual accessories too?\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003eIt is a mechanical spacer with no optical elements, so it carries through equally in an imaging or visual chain, provided the M98 thread on both sides lines up.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eBottom Line\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eA 32.5 mm M98 spacer ring for the CCA-250, built to work with the TKA86580L super reducer and camera rotator.\u003c\/p\u003e","brand":"Takahashi","offers":[{"title":"Default Title","offer_id":54047915311215,"sku":"TAK-TKP86002","price":127.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/takahashi-m98-extension-tube-32-5mm-tkp86002-astronomy-plus-1.jpg?v=1786936543"},{"product_id":"takahashi-m55-9-extension-tube-l30","title":"Takahashi M55.9 Extension Tube L30","description":"\u003ch3\u003e\u003cstrong\u003eProduct Overview\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eThe M55.9 Extension Tube L30 threads directly into the M55.9 x 0.75 accessory system shared across several Takahashi refractors. It carries no optics of its own — its whole job is moving a downstream accessory 30 mm further from the focuser, in one fixed step.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eWho It's For\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eThis is a good match if you're assembling a visual or imaging train on a Takahashi scope with an M55.9 x 0.75 drawtube thread and you need to add spacing without introducing a second reducer or flattener.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eKey Features \u0026amp; Design\u003c\/strong\u003e\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eM55.9 x 0.75 thread:\u003c\/strong\u003e matches the drawtube thread used on several Takahashi refractor accessory chains.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e30 mm light path:\u003c\/strong\u003e among the longer single spacers Takahashi offers on this thread, useful when a shorter ring won't close the gap to a flattener's backfocus target.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSolid metal construction:\u003c\/strong\u003e a single-piece spacer with no moving parts and nothing to align.\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003e\u003cstrong\u003eRecommended Uses\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eUse it to fine-tune spacing in an M55.9 visual or camera train — reaching a flattener's specified backfocus, for example, or adding clearance for a filter wheel or off-axis guider that would otherwise sit too close to the focuser.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eCompatibility and Accessory Notes\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eIt threads into any Takahashi accessory using the M55.9 x 0.75 standard. The published 30 mm is what it adds to your optical train, not its physical length measured end to end with calipers — the two numbers differ because of how far the threads seat into the mating parts on each side. The \u003ca href=\"\/pages\/takahashi-back-focus-guide\"\u003eTakahashi Back Focus Guide\u003c\/a\u003e tabulates this figure alongside the back focus target for every Takahashi telescope, so you can work out whether you need it before you order.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eFrequently Asked Questions\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eIs it difficult to set up?\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003eNo — it threads directly into the M55.9 accessory chain with no adjustment to make.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat is it best used for?\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003eAdding a fixed 30 mm of spacing to an M55.9 visual or imaging train.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eDoes it work for both visual and imaging setups?\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003eYes — it's a mechanical spacer with no optical element, so it works the same way in either train.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eBottom Line\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eAn M55.9 x 0.75 spacer that adds 30 mm to your optical train. If you're not sure whether this is the spacing figure you need, send us your current train and telescope model and we'll work it out with you.\u003c\/p\u003e","brand":"Takahashi","offers":[{"title":"Default Title","offer_id":54047915868271,"sku":"TAK-TKA18006","price":46.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/screenshot2024-09-18at120604pm_600x_b18d297c-b696-4412-a5fe-7f166c303f2b.jpg?v=1786936561"},{"product_id":"takahashi-cca-250-98mm-ext-aux-ring","title":"Takahashi CCA-250 98mm EXT AUX Ring","description":"\u003ch3\u003e\u003cstrong\u003eProduct Overview\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eThe 98mm EXT AUX Ring is a Takahashi M98 extension ring built for the CCA-250's camera train. It connects to the camera rotator through the TKA82595 connector, and the telescope-side M98 sleeves attach to it through the TKA86204 adapter.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eWho It's For\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eThis is a good match if you run a CCA-250 and need an additional M98 extension point between the telescope's M98 sleeves and the camera rotator.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eKey Features \u0026amp; Design\u003c\/strong\u003e\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eM98 thread family:\u003c\/strong\u003e matches the CCA-250's own accessory ring system.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eConnects to the camera rotator:\u003c\/strong\u003e pairs with the TKA82595 connector on the camera side.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eConnects to the telescope's M98 sleeves:\u003c\/strong\u003e pairs with the TKA86204 adapter on the telescope side.\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003e\u003cstrong\u003eRecommended Uses\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eExtending a CCA-250 imaging train between its M98 telescope-side sleeves and the camera rotator.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eCompatibility and Accessory Notes\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eBuilt for the CCA-250, using the TKA82595 connector on the camera-rotator side and the TKA86204 adapter on the telescope side. The \u003ca href=\"\/pages\/takahashi-back-focus-guide\"\u003eTakahashi Back Focus Guide\u003c\/a\u003e tabulates every Takahashi adapter's light path alongside each telescope's back focus target and is a good starting reference for the rest of your CCA-250 chain.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eFrequently Asked Questions\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eIs it difficult to set up?\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003eNo — it connects between the TKA86204 telescope-side adapter and the TKA82595 rotator connector with no adjustment.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat is it used for?\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003eExtending the CCA-250's M98 camera train between the telescope-side sleeves and the camera rotator.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eDoes it come with the TKA82595 or TKA86204 parts?\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003eNo — those are the connector and adapter it pairs with on either side, and are separate parts.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eBottom Line\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eAn M98 extension ring for the CCA-250's camera train, bridging the telescope-side sleeves and camera rotator.\u003c\/p\u003e","brand":"Takahashi","offers":[{"title":"Default Title","offer_id":54047916294255,"sku":"TAK-TKA86596","price":130.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/takahashi-m98-extension-tube-for-cca-250-tka86596-astronomy-plus-1.jpg-2.jpg?v=1786936570"},{"product_id":"takahashi-f-6-visual-extension-tube","title":"Takahashi f\/6 Visual Extension Tube","description":"\u003ch3\u003e\u003cstrong\u003eProduct Overview\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eThe f\/6 Visual Extension Tube is Takahashi's Extension Tube (S) — a short M43 x 0.75 spacer for f\/6 Takahashi refractors that adds a published 26 mm to a visual train. It's the shorter of Takahashi's two M43 extension tubes, plain machined metal with no optics of its own.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eWho It's For\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eThis is a good match if your f\/6 Takahashi refractor is coming up short of focus with a diagonal, eyepiece holder, or other M43-threaded accessory and needs a modest amount of extra in-travel.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eKey Features \u0026amp; Design\u003c\/strong\u003e\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eM43 x 0.75 thread:\u003c\/strong\u003e Takahashi's standard visual-accessory thread on f\/6 models.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eExtension Tube (S) — part TKP00105:\u003c\/strong\u003e Takahashi's own designation for this specific length.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e26 mm light path:\u003c\/strong\u003e enough to bring an eyepiece or diagonal back into focus range without over-extending the train.\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003e\u003cstrong\u003eRecommended Uses\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eUse it to add 26 mm of spacing ahead of a diagonal or eyepiece holder on an M43-threaded Takahashi visual train, or to reach focus where the stock drawtube travel falls short.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eCompatibility and Accessory Notes\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eIt threads onto Takahashi's M43 x 0.75 visual accessory standard. The published 26 mm is what it adds to the optical train, not the figure you'd get from measuring the tube end to end with calipers — thread engagement on each side changes where the light path actually starts and stops. The \u003ca href=\"\/pages\/takahashi-back-focus-guide\"\u003eTakahashi Back Focus Guide\u003c\/a\u003e tabulates this figure next to every Takahashi telescope's back focus target.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eFrequently Asked Questions\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eIs it difficult to set up?\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003eNo — it threads directly into the M43 visual train with nothing to align.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat is it best used for?\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003eAdding 26 mm of spacing to reach focus or hit a specific backfocus figure in a visual train.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow is it different from the f\/8 Visual Extension Tube?\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003eTakahashi lists it as the Extension Tube (S) — 26 mm, against the Extension Tube (L)'s 34 mm.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eBottom Line\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eA 26 mm M43 extension tube built for f\/6 Takahashi visual trains. If you're unsure whether the 26 mm or 34 mm tube is the one you need, send us your telescope and eyepiece setup and we'll work it out with you.\u003c\/p\u003e","brand":"Takahashi","offers":[{"title":"Default Title","offer_id":54047916851311,"sku":"TAK-TKP00105","price":61.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/tsp0050_2_6.jpg?v=1786936588"},{"product_id":"takahashi-fsq-130ed-aux-ring-27-5mm","title":"Takahashi FSQ-130ED Aux Ring 27.5mm","description":"\u003ch3\u003e\u003cstrong\u003eProduct Overview\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eThe Aux Ring (FSQ-130) is Takahashi's Aux. Ring (S) for the FSQ-130ED, with a published light path of 27.5 mm — the amount it contributes to your optical train, not its physical length end to end.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eWho It's For\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eThis is a good match if you own an FSQ-130ED and are building out its camera or accessory train and need this defined 27.5 mm connection point.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eKey Features \u0026amp; Design\u003c\/strong\u003e\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003e27.5 mm published light path:\u003c\/strong\u003e a fixed, known contribution to your back focus total.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eBuilt for the FSQ-130ED:\u003c\/strong\u003e matches this telescope's own accessory ring family rather than a universal fitting.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSingle-piece metal ring:\u003c\/strong\u003e no moving parts to maintain.\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003e\u003cstrong\u003eRecommended Uses\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eExtending or completing the camera or accessory chain on an FSQ-130ED for imaging.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eCompatibility and Accessory Notes\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eBuilt for the FSQ-130ED. The 27.5 mm figure is worth adding to your full back-focus total alongside any reducer, flattener, or filter wheel already in the chain — the \u003ca href=\"\/pages\/takahashi-back-focus-guide\"\u003eTakahashi Back Focus Guide\u003c\/a\u003e tabulates every Takahashi adapter's light path alongside each telescope's back focus target.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eFrequently Asked Questions\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eIs it difficult to set up?\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003eNo — it is a single ring with no adjustment.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat is it used for?\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003eAdding a defined 27.5 mm connection point in the FSQ-130ED's camera or accessory train.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs it specific to the FSQ-130ED?\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003eYes — Takahashi lists it specifically for the FSQ-130ED rather than as a universal ring.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eBottom Line\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eA 27.5 mm light-path Aux Ring built for the FSQ-130ED's camera and accessory train.\u003c\/p\u003e","brand":"Takahashi","offers":[{"title":"Default Title","offer_id":54047917080687,"sku":"TAK-TKA38205","price":134.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/screenshot_2026-08-26_at_2.57.07_pm.png?v=1787841794"},{"product_id":"takahashi-f-8-visual-extension-tube","title":"Takahashi f\/8 Visual Extension Tube","description":"\u003ch3\u003e\u003cstrong\u003eProduct Overview\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eThe f\/8 Visual Extension Tube is Takahashi's Extension Tube (L) — a short M43 x 0.75 spacer for f\/8 Takahashi refractors that adds a published 34 mm to a visual train. It's the longer of Takahashi's two M43 extension tubes, plain machined metal with no optics of its own.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eWho It's For\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eThis is a good match if your f\/8 Takahashi refractor needs more in-travel than a diagonal or eyepiece holder alone can reach on an M43-threaded accessory chain.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eKey Features \u0026amp; Design\u003c\/strong\u003e\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eM43 x 0.75 thread:\u003c\/strong\u003e Takahashi's standard visual-accessory thread on f\/8 models.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eExtension Tube (L) — part TKP00106:\u003c\/strong\u003e Takahashi's own designation for this specific length.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e34 mm light path:\u003c\/strong\u003e the longer reach in Takahashi's M43 extension pair, useful when the shorter S tube still leaves you short of focus.\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003e\u003cstrong\u003eRecommended Uses\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eUse it to add 34 mm of spacing ahead of a diagonal or eyepiece holder on an M43-threaded Takahashi visual train, or to reach focus where the stock drawtube travel falls short.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eCompatibility and Accessory Notes\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eIt threads onto Takahashi's M43 x 0.75 visual accessory standard. The published 34 mm is what it adds to the optical train, not the figure you'd get from measuring the tube end to end with calipers — thread engagement on each side changes where the light path actually starts and stops. The \u003ca href=\"\/pages\/takahashi-back-focus-guide\"\u003eTakahashi Back Focus Guide\u003c\/a\u003e tabulates this figure next to every Takahashi telescope's back focus target.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eFrequently Asked Questions\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eIs it difficult to set up?\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003eNo — it threads directly into the M43 visual train with nothing to align.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat is it best used for?\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003eAdding 34 mm of spacing to reach focus or hit a specific backfocus figure in a visual train.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow is it different from the f\/6 Visual Extension Tube?\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003eTakahashi lists it as the Extension Tube (L) — 34 mm, against the Extension Tube (S)'s 26 mm.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eBottom Line\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eA 34 mm M43 extension tube built for f\/8 Takahashi visual trains. If you're unsure whether the 26 mm or 34 mm tube is the one you need, send us your telescope and eyepiece setup and we'll work it out with you.\u003c\/p\u003e","brand":"Takahashi","offers":[{"title":"Default Title","offer_id":54047917146223,"sku":"TAK-TKP00106","price":61.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/tsp0060_2_6.jpg?v=1786936601"},{"product_id":"takahashi-vari-ring-spacer","title":"Takahashi Vari-Ring Spacer","description":"\u003ch3\u003e\u003cstrong\u003eProduct Overview\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eThe Vari-Ring Spacer is a Takahashi M72 x 1.0 ring built for one job on the TOA telescope series: shifting how much reduction the matched reducer actually delivers. Takahashi publishes its light path at 17 mm — add it ahead of a TOA reducer and the effective reduction ratio changes with it.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eWho It's For\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eThis is a good match if you're running a TOA-series reducer and want to fine-tune the reduction ratio, or you're matching a published system chart that calls for the Vari-Ring specifically.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eKey Features \u0026amp; Design\u003c\/strong\u003e\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eM72 x 1.0 thread on both ends:\u003c\/strong\u003e male on one side, female on the other, so it drops straight into the M72 reducer chain.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e17 mm light path:\u003c\/strong\u003e enough to noticeably shift a TOA reducer's effective ratio without swapping the reducer itself.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTakahashi part TKA31581\u003c\/strong\u003e — Takahashi's own \"Vari-Ring\" designation.\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003e\u003cstrong\u003eRecommended Uses\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eUse it between a TOA-series reducer and the rest of the imaging train to shift the effective reduction ratio, per Takahashi's published system chart for your telescope.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eCompatibility and Accessory Notes\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eIt fits Takahashi's M72 x 1.0 accessory system used on the TOA series. The 17 mm figure is what it contributes to the optical train, not its physical length end to end — the male and female M72 threads seat differently than a caliper measurement would suggest. The \u003ca href=\"\/pages\/takahashi-back-focus-guide\"\u003eTakahashi Back Focus Guide\u003c\/a\u003e lists this figure next to the back focus target for each TOA model, so you can check the total spacing before ordering.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eFrequently Asked Questions\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eIs it difficult to set up?\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003eNo — it threads into the M72 reducer chain like any other ring in the system.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat is it best used for?\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003eAdjusting the effective reduction of a TOA-series reducer by changing the spacing ahead of it.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eDoes it work with reducers outside the TOA series?\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003eTakahashi documents it for the TOA series specifically. If you're matching a different M72 reducer, send us your telescope and reducer model and we'll confirm the fit.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eBottom Line\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eAn M72 x 1.0 spacer built to dial in the reduction on a TOA-series reducer, adding 17 mm to the optical train in the process.\u003c\/p\u003e","brand":"Takahashi","offers":[{"title":"Default Title","offer_id":54047917539439,"sku":"TAK-TKA31581","price":63.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/tka31581_2_6.jpg?v=1786936615"},{"product_id":"takahashi-tsa-102-m72-to-f72-aux-extension-tube-52mm","title":"Takahashi TSA-102 M72 to F72 Aux Extension Tube 52mm","description":"\u003ch3\u003e\u003cstrong\u003eProduct Overview\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eThe M72 to F72 Aux Extension Tube is Takahashi's Aux. Ring (FB TSA-102mm), threading M72 x 1.0 into the TSA-102's camera-side connection. It carries a published light path of 52 mm — the amount it contributes to your optical train, not its physical length end to end.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eWho It's For\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eThis is a good match if you own a TSA-102 and need 52 mm of additional M72 spacing to reach a target back focus for imaging or to fit a 2\" visual accessory further out.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eKey Features \u0026amp; Design\u003c\/strong\u003e\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eM72 x 1.0 thread throughout:\u003c\/strong\u003e matches the TSA-102's own camera-side interface at both ends.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e52 mm published light path:\u003c\/strong\u003e a fixed, known contribution to your back focus total.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e2\" clear aperture:\u003c\/strong\u003e passes a full 2\" light cone without vignetting concerns from the tube itself.\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003e\u003cstrong\u003eRecommended Uses\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eAdding 52 mm of M72 spacing to a TSA-102 imaging train, or extending the reach of a 2\" visual accessory chain.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eCompatibility and Accessory Notes\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eBuilt for the TSA-102, with M72 x 1.0 threading on both ends. At 52 mm, it is a substantial part of most back-focus budgets, so it is worth checking against your camera, flattener, and any other spacers already in the train — the \u003ca href=\"\/pages\/takahashi-back-focus-guide\"\u003eTakahashi Back Focus Guide\u003c\/a\u003e tabulates every Takahashi adapter's light path alongside each telescope's back focus target.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eGood to Know Before You Order\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003e52 mm is a large fixed step:\u003c\/strong\u003e because it cannot be trimmed, it is worth confirming it lands your train at the right total before ordering rather than after. Send us your full imaging or visual setup and we will work out the spacing with you.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eFrequently Asked Questions\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eIs it difficult to set up?\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003eNo — it threads in at both ends with no adjustment involved.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat is it used for?\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003eAdding a fixed 52 mm of M72 spacing in a TSA-102 imaging or visual accessory train.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eDoes it work for both visual and imaging use?\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003eYes — it is a mechanical extension tube with a full 2\" clear aperture, so it carries through either a visual or imaging chain.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eBottom Line\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eA 52 mm light-path, M72 extension tube for the TSA-102. It is worth confirming against the rest of your train before ordering, given the size of the step.\u003c\/p\u003e","brand":"Takahashi","offers":[{"title":"Default Title","offer_id":54047917736047,"sku":"TAK-TKA23250","price":139.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/tka23250_3.jpg?v=1786936622"},{"product_id":"takahashi-photo-tube-extension-dt","title":"Takahashi Photo Tube Extension DT","description":"\u003ch3\u003e\u003cstrong\u003eProduct Overview\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eThe Photo Tube Extension DT is Takahashi's Coupling (DT), an M55.9 x 0.75 ring built specifically for the \"DT\" photo\/visual train. Takahashi publishes its light path at 18 mm, and it comes with one notable restriction: it won't thread onto every M55.9 part in the lineup.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eWho It's For\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eThis is a good match if your Takahashi system chart calls for the Coupling (DT) specifically, or you're assembling a camera train on the M55.9 accessory standard and need this exact spacing.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eKey Features \u0026amp; Design\u003c\/strong\u003e\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eM55.9 x 0.75 thread:\u003c\/strong\u003e Takahashi's drawtube-accessory standard shared across several refractors.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCoupling (DT) — Takahashi part TKP20006B:\u003c\/strong\u003e the manufacturer's own designation.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e18 mm light path:\u003c\/strong\u003e a mid-length step in the M55.9 family, between the 10 mm Visual Coupling S and the 30 mm Extension Tube L30.\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003e\u003cstrong\u003eRecommended Uses\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eUse it in an M55.9 camera train where the published system chart specifies the Coupling (DT) — typically to reach a flattener or reducer's stated backfocus.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eCompatibility and Accessory Notes\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eIt threads onto Takahashi's M55.9 x 0.75 accessory standard. Takahashi's own documentation notes that this coupling and the M55.9 Extension Tube L30 cannot be screwed onto the female thread of the Camera Angle Adjuster S — worth checking against your system chart before ordering. Its 18 mm light path is what it adds to the optical train, not a caliper measurement of the physical part. The \u003ca href=\"\/pages\/takahashi-back-focus-guide\"\u003eTakahashi Back Focus Guide\u003c\/a\u003e tabulates this figure alongside every Takahashi telescope's back focus target.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eGood to Know Before You Order\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eIt does not thread onto the Camera Angle Adjuster S's female thread.\u003c\/strong\u003e Takahashi documents this specifically — if your train includes the Camera Angle Adjuster S, send us your full setup and we'll confirm what does fit.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eFrequently Asked Questions\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eIs it difficult to set up?\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003eNo — it threads into the M55.9 chain directly, aside from the Camera Angle Adjuster S exception noted above.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat is it best used for?\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003eAdding a fixed 18 mm of spacing in an M55.9 photo\/visual train, per Takahashi's system chart.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs it a visual-only part or does it work for imaging too?\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003eTakahashi designates it \"DT\" for its photo\/visual train, and it carries no optics, so it works the same mechanically in either use.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eBottom Line\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eAn M55.9 coupling that adds a published 18 mm to the light path, built for Takahashi's DT photo\/visual train — with the one Camera Angle Adjuster S exception worth checking first.\u003c\/p\u003e","brand":"Takahashi","offers":[{"title":"Default Title","offer_id":54047917965423,"sku":"TAK-TKP20006B","price":63.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/tkp20006b_3.jpg?v=1786936629"},{"product_id":"takahashi-2-extension-tube-l","title":"Takahashi 2\" Extension Tube (L)","description":"\u003ch3\u003e\u003cstrong\u003eProduct Overview\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eTakahashi's Extension Tube (L) (50.8), part TKP31112, is a 2-inch sleeve that lengthens a Takahashi imaging or visual train. Takahashi publishes a light path length of 73.5 mm for it — not its physical size, but what it adds once it's in the train — and it's the longer of Takahashi's two 50.8 mm extension tubes; the shorter Extension Tube (50.8) (TKP27112) adds 62 mm instead.\u003c\/p\u003e\u003cp\u003eAt 73.5 mm it's a substantial step, useful when a shorter extension leaves you short of focus or short of a flattener's specified backfocus.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eWho It's For\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eThis is a good match if your setup needs roughly 73.5 mm of additional 2-inch spacing to reach focus or hit a flattener's specified backfocus — on a TOA-130 imaging train, for instance, where Takahashi lists it as a compatible accessory.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eKey Features \u0026amp; Design\u003c\/strong\u003e\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003e50.8 mm sleeve:\u003c\/strong\u003e accepts standard 2-inch fittings on both ends.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e73.5 mm light path length:\u003c\/strong\u003e Takahashi's published figure for the spacing this tube adds.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eBlack anodized finish:\u003c\/strong\u003e non-reflective inside the light path.\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003e\u003cstrong\u003eRecommended Uses\u003c\/strong\u003e\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eReaching focus\u003c\/strong\u003e in trains with a long inward-travel requirement.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eHitting a flattener or reducer's specified backfocus,\u003c\/strong\u003e where the shorter extension tube falls short.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eExtending a TOA-130 imaging or visual train,\u003c\/strong\u003e where Takahashi lists it as a compatible part.\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003e\u003cstrong\u003eCompatibility and Accessory Notes\u003c\/strong\u003e\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003e50.8 mm sleeve fitting\u003c\/strong\u003e on both ends, compatible with Takahashi's 2-inch accessory system.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAdds 73.5 mm to the optical path\u003c\/strong\u003e — worth working into a full train calculation before you order. Our \u003ca href=\"\/pages\/takahashi-back-focus-guide\"\u003eTakahashi Back Focus Guide\u003c\/a\u003e lists it alongside the back focus figures for each telescope.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePurely mechanical\u003c\/strong\u003e — no optical element, no change to focal length or focal ratio.\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003e\u003cstrong\u003eGood to Know Before You Order\u003c\/strong\u003e\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eIt's the longer of two similar Takahashi extension tubes.\u003c\/strong\u003e The shorter Extension Tube (50.8) adds 62 mm rather than 73.5 mm — tell us your target spacing and we'll confirm which one you need.\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003e\u003cstrong\u003eFrequently Asked Questions\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eIs it difficult to set up?\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003eNo — it's a straight sleeve that fits between two 2-inch fittings, with nothing to align.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow much does it add to my optical train?\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003e73.5 mm — send us your full train if you'd like it checked against a flattener's backfocus spec before you order.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs there a shorter version?\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003eYes — Takahashi's Extension Tube (50.8) adds 62 mm instead, sold as a separate part.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eDoes it include any optics?\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003eNo. It's a mechanical adapter only.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eBottom Line\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eIn short: Takahashi's 2-inch Extension Tube (L) — a 50.8 mm sleeve adding 73.5 mm of light path, for trains that need the longer of Takahashi's two standard extension steps.\u003c\/p\u003e","brand":"Takahashi","offers":[{"title":"Default Title","offer_id":54047927173231,"sku":"TAK-TKP31112","price":244.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/tet0002l_2_6.jpg?v=1786936711"},{"product_id":"takahashi-36-5mm-2-accessory-extension-tube-for-eyepiece-turret","title":"Takahashi 36.5mm 2\" Accessory Extension Tube for Eyepiece Turret","description":"\u003ch3\u003e\u003cstrong\u003eProduct Overview\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eA 36.5 mm 2″ extension tube for the Takahashi eyepiece turret. On several Takahashi telescopes the turret will not reach focus without it, so this tube is a requirement rather than an option on those models — it adds the back-focus the turret needs to come to focus in the drawtube.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eWho It's For\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eThis is a good match if you are running — or about to buy — the Takahashi 4-turret eyepiece holder on one of the telescopes listed below.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eKey Features \u0026amp; Design\u003c\/strong\u003e\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003e36.5 mm optical length:\u003c\/strong\u003e the extension the turret needs to reach focus.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e2″ format:\u003c\/strong\u003e matches the turret's 2″ nosepiece fitting.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMechanical only:\u003c\/strong\u003e a spacing component with no optical elements — it does not change magnification or field.\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003e\u003cstrong\u003eRecommended Uses\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eVisual observing with the Takahashi 4-turret eyepiece holder, where four eyepieces stay mounted and rotate into place.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eCompatibility and Accessory Notes\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eTakahashi lists this extension as required for turret use on the \u003cstrong\u003eFC-76S, FSQ-85, FSQ-106ED, FSQ-130ED, Mewlon-250CRS and Mewlon-300CRS\u003c\/strong\u003e. If your telescope is not on that list and you are planning a turret, send us the model and we will work out the back-focus with you before you order.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eGood to Know Before You Order\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eRequired, not optional, on the listed telescopes:\u003c\/strong\u003e the turret will not reach focus on those models without this tube, so the two are bought together.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eThe turret is separate:\u003c\/strong\u003e this listing is the extension tube alone. We stock the 4-turret eyepiece holder as well.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eFrequently Asked Questions\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eIs it difficult to set up?\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003eNo — it goes between the drawtube and the turret's 2″ nosepiece, and nothing needs adjusting afterwards.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhich telescopes need it?\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003eThe FC-76S, FSQ-85, FSQ-106ED, FSQ-130ED, Mewlon-250CRS and Mewlon-300CRS.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eDoes it change magnification?\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003eNo — it has no optical elements. It is spacing only.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eDo I need it if I am not using a turret?\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003eNo — it exists specifically to give the turret the back-focus it needs.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eBottom Line\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eThe 36.5 mm 2″ extension that lets the Takahashi eyepiece turret reach focus on the FSQ, FC-76S and Mewlon CRS telescopes.\u003c\/p\u003e","brand":"Takahashi","offers":[{"title":"Default Title","offer_id":54085941854319,"sku":"TAK-TKA00105","price":208.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/4-turret-takahashi_1_2_2.jpg?v=1787328653"},{"product_id":"takahashi-kb-spacer-set-of-2","title":"KB Spacer - Set of 2","description":"\u003ch3\u003e\u003cstrong\u003eProduct Overview\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eThe KB Spacer 45B is a pair of machined blocks that sit between a Takahashi tube band and the dovetail rail beneath it, raising the band by 19 mm. Each block measures 45 mm long, 17 mm wide and 19 mm high, and weighs about 30 g — the set contains two.\u003c\/p\u003e\u003cp\u003eTakahashi lists it for the \u003cstrong\u003e95WB\u003c\/strong\u003e and \u003cstrong\u003e80WB\u003c\/strong\u003e tube bands. All the hardware for both interfaces is in the box: two M6×20 cap bolts to fix the spacers to the band, and four M6×30 cap bolts to mount the assembly to the dovetail.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eWho It's For\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eThis is a good match if you are running an 80WB or 95WB tube band and need to lift the optical tube clear of whatever sits on the dovetail — or to raise it far enough that a focuser, camera or finder at the rear does not foul the rail or the mount head.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eKey Features \u0026amp; Design\u003c\/strong\u003e\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003e19 mm of added height:\u003c\/strong\u003e the block's height, between band and dovetail.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e45 × 17 × 19 mm per block:\u003c\/strong\u003e two supplied per set, about 30 g each.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFive mounting points:\u003c\/strong\u003e four M6 through-holes, plus one M6 through-hole counterbored Ø11 × 6.5 mm.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eBolts included for both ends:\u003c\/strong\u003e 2 × M6×20 for the band, 4 × M6×30 for the dovetail.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMechanical only:\u003c\/strong\u003e no optical elements — it changes height, nothing else.\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003e\u003cstrong\u003eRecommended Uses\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eRaising an 80WB or 95WB band on its dovetail to clear an obstruction, gain focuser or camera clearance at the rear of the tube, or adjust where the tube sits relative to the mount.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eCompatibility and Accessory Notes\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eTakahashi specifies this spacer for the \u003cstrong\u003e95WB\u003c\/strong\u003e and \u003cstrong\u003e80WB\u003c\/strong\u003e tube bands. If you are pairing spacers with a band, get in touch and we will bring the matching band in alongside them.\u003c\/p\u003e\u003cp\u003eThe mounting pattern is M6 throughout, matching Takahashi's own dovetail hardware. If you are fitting these to a third-party dovetail or plate, send us what you are mounting to and we will check the bolt pattern against it before you order.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eGood to Know Before You Order\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eSold as a pair:\u003c\/strong\u003e two spacers per set, which is what a two-ring band needs — one under each ring.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eSpecified for two bands:\u003c\/strong\u003e the 80WB and 95WB. If your band is a different Takahashi model, tell us which and we will confirm the fit rather than have you guess.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eThe bolts are in the box:\u003c\/strong\u003e both the band-fixing and dovetail-mounting bolts are supplied, so there is nothing else to source.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eFrequently Asked Questions\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eIs it difficult to set up?\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003eNo — the spacers bolt to the underside of the band with the supplied M6×20 bolts, and the longer M6×30 bolts pass through into the dovetail. It is a straight swap into the existing bolt path.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow much height does it add?\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003e19 mm.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow many are in the set?\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003eTwo, one for each ring of the band.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhich bands does it fit?\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003eThe 95WB and the 80WB.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eDo I need to buy bolts separately?\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003eNo — two M6×20 and four M6×30 cap bolts are supplied.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eBottom Line\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eA pair of 19 mm spacer blocks that lift an 80WB or 95WB tube band off its dovetail, with the bolts for both ends included.\u003c\/p\u003e","brand":"Takahashi","offers":[{"title":"Default Title","offer_id":54086149079151,"sku":"TAK-TKB11425","price":60.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/tkb11425-1.jpg?v=1787329436"}],"url":"https:\/\/ontariotelescope.com\/collections\/extension-tubes-and-spacers.oembed","provider":"Ontario Telescope and Accessories","version":"1.0","type":"link"}