{"product_id":"explore-scientific-ed80-fcd100-triplet-refractor-field-flattener","title":"Explore Scientific ED80-FCD100 80mm f\/6 Air-Spaced Triplet Refractor with Field Flattener","description":"\u003ch2\u003eProduct Overview\u003c\/h2\u003e\u003cp\u003eThe Explore Scientific ED80-FCD100 is an 80 mm f\/6 air-spaced apochromatic triplet refractor built with HOYA FCD-100 extra-low-dispersion glass. Focal length is 480 mm and the tube assembly weighs 7.5 lb. This configuration pairs the telescope with the Explore Scientific Field Flattener for f\/5 to f\/7 refractors, which corrects the field curvature that otherwise smears stars toward the corners of a long exposure.\u003c\/p\u003e\u003ch2\u003eWho It's For\u003c\/h2\u003e\u003cp\u003eThis is aimed at the imager who wants flat, round stars across the whole frame at the telescope's native f\/6 rather than a faster reduced focal ratio. Where the 0.8x reducer version trades focal length for speed, this configuration keeps all 480 mm and spends the correction on field flatness — the better choice for larger camera sensors and for anyone who prefers native framing.\u003c\/p\u003e\u003ch2\u003eKey Features \u0026amp; Design\u003c\/h2\u003e\u003cul\u003e\n\u003cli\u003eHOYA FCD-100 ED glass in an air-spaced triplet objective\u003c\/li\u003e\n\u003cli\u003eIncluded field flattener matched to f\/5 through f\/7 refractors for edge-to-edge star sharpness\u003c\/li\u003e\n\u003cli\u003e2.5-inch hexagonal rack-and-pinion focuser rated for 10 lb of imaging equipment\u003c\/li\u003e\n\u003cli\u003e99% reflective 2-inch dielectric diagonal included for visual observing\u003c\/li\u003e\n\u003cli\u003eTwo focuser extension tubes for reaching focus across different trains\u003c\/li\u003e\n\u003cli\u003eRetractable dew shield and Vixen-style dovetail\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch2\u003eOptical and Mechanical Design\u003c\/h2\u003e\u003cp\u003eField curvature grows worse as focal ratio gets faster and as sensors get larger; uncorrected, stars near the frame edge stretch radially into small comet shapes. The field flattener sits in the imaging train ahead of the camera and returns the focal plane to flat, so stars at the corners focus at the same point as those at centre. Resolution is 1.45 arcseconds, limiting magnitude 12. The tube runs 18.5 inches with the dew shield extended, 15 inches retracted, 85 mm in diameter.\u003c\/p\u003e\u003ch2\u003eRecommended Uses\u003c\/h2\u003e\u003cul\u003e\n\u003cli\u003eDeep-sky imaging at native f\/6 with round stars to the frame corners\u003c\/li\u003e\n\u003cli\u003eImaging with APS-C and larger sensors, where field curvature shows most\u003c\/li\u003e\n\u003cli\u003eVisual observing of the Moon, planets, and double stars with the included diagonal\u003c\/li\u003e\n\u003cli\u003eMosaic and multi-panel projects that need consistent star shapes across panels\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch2\u003eCompatibility and Accessory Notes\u003c\/h2\u003e\u003cp\u003eThe flattener is specified for refractors between f\/5 and f\/7, which covers this telescope at f\/6. The Vixen-style dovetail fits standard Vixen saddles including the iEXOS-100-2 and EXOS-2GT. Reaching correct spacing between flattener and sensor is what determines corner performance, so plan on the T-thread adapters and spacers that match your camera; our team can work out the stack for your body. A finder scope is not included.\u003c\/p\u003e\u003ch2\u003eGood to Know Before You Order\u003c\/h2\u003e\u003cp\u003eMount, tripod, eyepieces, camera adapters, and finder scope are separate purchases. Explore Scientific does not publish a \"what's in the box\" list for this configuration, so the included-items detail above reflects the tube and flattener specifications they do publish; contact us if you need the packing list confirmed before ordering. Published tube weight is 7.5 lb, and the shipping weight at checkout is rounded up to the next whole pound.\u003c\/p\u003e\u003ch2\u003eFrequently Asked Questions\u003c\/h2\u003e\u003cp\u003e\u003cstrong\u003eIs it difficult to set up?\u003c\/strong\u003e The telescope itself is simple — dovetail into the saddle, dew shield out by hand. The one job that rewards care is setting flattener-to-sensor spacing, and we can specify the adapters for your camera so it is right the first time.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eFlattener or 0.8x reducer — which should I choose?\u003c\/strong\u003e The flattener keeps 480 mm at f\/6 and flattens the field. The reducer shortens to 384 mm at f\/4.8 for shorter exposures and wider framing. Larger sensors and native framing favour the flattener.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eCan I observe visually with it?\u003c\/strong\u003e Yes. Fit the included 2-inch diagonal and an eyepiece.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWill it work on a small mount?\u003c\/strong\u003e It needs a mount rated comfortably past 7.5 lb plus camera and accessories. The iEXOS-100-2 is a common pairing.\u003c\/p\u003e\u003ch2\u003eBottom Line\u003c\/h2\u003e\u003cp\u003eAn 80 mm FCD-100 apochromat supplied with the matching field flattener, for imagers who want native focal length and clean stars in the corners. Get in touch and we will spec the spacing for your camera.\u003c\/p\u003e","brand":"Explore Scientific","offers":[{"title":"Default Title","offer_id":53955258548335,"sku":"ES-FCD100-0806-FF","price":1149.95,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/FCD100-0806-02-FF.jpg?v=1785951047","url":"https:\/\/ontariotelescope.com\/products\/explore-scientific-ed80-fcd100-triplet-refractor-field-flattener","provider":"Ontario Telescope and Accessories","version":"1.0","type":"link"}