{"product_id":"0-75x-reducer-for-askar-91f","title":"0.75x Reducer for Askar 91F","description":"\u003cp\u003eThe 0.75x reducer can bring Askar 91F's focal ratio down to F5, 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\u003ch3 class=\"e_h3-72 s_summary response-transition\"\u003eSpecifications\u003c\/h3\u003e\n\u003cdiv class=\"e_richText-73 s_title clearfix response-transition\"\u003e\n\u003cfigure class=\"table\"\u003e\n\u003ctable\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd style=\"text-align: center;\" colspan=\"2\"\u003e\u003cstrong\u003eParameter\u003c\/strong\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"text-align: center;\"\u003e\u003cstrong\u003e （After attaching）91F Focal length\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"text-align: center;\"\u003e\u003cstrong\u003e455mm\u003c\/strong\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"text-align: center;\"\u003e\u003cstrong\u003e （After attaching）91F Focal ratio\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"text-align: center;\"\u003e\u003cstrong\u003ef\/5\u003c\/strong\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"text-align: center;\"\u003e\u003cstrong\u003eLens Number\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"text-align: center;\"\u003e\u003cstrong\u003eTriplet design\u003c\/strong\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"text-align: center;\"\u003e\u003cstrong\u003eBack Focus\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"text-align: center;\"\u003e\u003cstrong\u003e55mm（from the base of M48 male thread）\u003c\/strong\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"text-align: center;\"\u003e\u003cstrong\u003eWeight\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"text-align: center;\"\u003e\u003cstrong\u003e0.3kg\u003c\/strong\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"text-align: center;\"\u003e\u003cstrong\u003eRear-end thread type\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"text-align: center;\"\u003e\u003cstrong\u003eM59*1\u003c\/strong\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/figure\u003e\n\u003c\/div\u003e","brand":"Askar","offers":[{"title":"Default Title","offer_id":50268629074177,"sku":"ASKAR-91F-75R","price":199.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0327\/2569\/6648\/files\/91F_FR_A.png?v=1789593810","url":"https:\/\/starizona.com\/products\/0-75x-reducer-for-askar-91f","provider":"Starizona","version":"1.0","type":"link"}