{"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","url":"https:\/\/ontariotelescope.com\/products\/player-one-m48f-m42m-17-5mm-extender","provider":"Ontario Telescope and Accessories","version":"1.0","type":"link"}