{"product_id":"askar-0-75x-91f-reducer-askar91fr","title":"Askar 0.75x 91F Reducer (ASKAR91FR)","description":"\u003cp\u003eThe 0.75x reducer can bring Askar 91F's focal ratio down to F\/5, providing not only a faster focal ratio but also built-in field-flattening correction. The shorter focal ratio delivers a wider field of view and a faster exposure time, making it ideal for capturing large areas of nebulae, star clusters, and faint, fast-moving celestial objects.\u003c\/p\u003e\n\u003cp\u003eThe 91F 0.75x reducer adopts a triplet design and supports a 44mm full-frame image circle. The back focus from the M48 thread is a standard 55mm. Both end threads are M59*1. The 91F photographic extension tube includes M54×0.75 and M48×0.75 adapters for direct and convenient connection to the 0.75x reducer. The reducer features a built-in M48*0.75 2-inch filter thread, allowing for direct filter installation and use. The entire reducer is CNC-machined and comes with front and rear metal threaded caps to protect against dust when not in use.\u003c\/p\u003e\n\u003cp\u003eConstructed using CNC machining, the reducer boasts a great finish and comes with front and rear metal thread caps for dust protection during storage.\u003c\/p\u003e\n\u003ch2\u003eSpecifications\u003c\/h2\u003e\n\u003ctable\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003e(After attaching) 91F Focal length\u003c\/td\u003e\n\u003ctd\u003e455mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e(After attaching) 91F Focal ratio\u003c\/td\u003e\n\u003ctd\u003ef\/5.0\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eLens Number\u003c\/td\u003e\n\u003ctd\u003eTriplet design\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBack Focus\u003c\/td\u003e\n\u003ctd\u003e55mm (from the base of M48 male thread)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWeight\u003c\/td\u003e\n\u003ctd\u003e0.30kg\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eRear-end thread type\u003c\/td\u003e\n\u003ctd\u003eM59*1\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003cp\u003e\u003cimg alt=\"\" src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0610\/7702\/9116\/files\/ASKAR91FR-DIMENSIONS.webp?v=1764733308\"\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cimg alt=\"\" src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0610\/7702\/9116\/files\/ASKAR91FR-INSTALLATION.webp?v=1764733308\"\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cimg alt=\"\" src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0610\/7702\/9116\/files\/ASKAR91FR-SPOT-DIAGRAM.webp?v=1764733308\"\u003e\u003c\/p\u003e","brand":"SharpStar","offers":[{"title":"Default Title","offer_id":48573735207164,"sku":"ASKAR91FR","price":274.95,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0610\/7702\/9116\/files\/ASKAR91FR-1.png?v=1764733308","url":"https:\/\/all-startelescope.com\/fr\/products\/askar-0-75x-91f-reducer-askar91fr","provider":"All-Star Telescope Canada","version":"1.0","type":"link"}