{"product_id":"sky-watcher-m48-camera-adapter-for-canon-dslr","title":"Sky-Watcher M48 Camera Adapter for Canon DSLR","description":"\u003ch3\u003e\u003cstrong\u003eProduct Overview\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eThis is the ring that joins a Canon DSLR body to a Sky-Watcher 0.85x Focal Reducer\/Corrector. One face carries an M48 thread that screws onto the corrector's camera-side output; the other is a Canon DSLR bayonet that the body twists and locks into. Sky-Watcher publishes it for the Esprit and ProED series when those telescopes are running their dedicated field correctors. The ring weighs 45 g.\u003c\/p\u003e\n\n\u003ch3\u003e\u003cstrong\u003eWho It's For\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eThis is the adapter for a Canon DSLR going onto a Sky-Watcher 0.85x reducer\/corrector on an Esprit or ProED refractor. It replaces the standard T-ring in that position, because the correctors output M48 rather than the T-thread that a T-ring uses. If your imaging camera is a dedicated astronomy camera rather than a DSLR, that camera's own M48 spacing hardware takes this place instead.\u003c\/p\u003e\n\n\u003ch3\u003e\u003cstrong\u003eKey Features \u0026amp; Design\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eM48 telescope-side thread:\u003c\/strong\u003e matches the output thread on Sky-Watcher's 0.85x Focal Reducer\/Correctors. Sky-Watcher notes M48 is used for larger-format imaging, where the wider thread keeps the light cone clear of the adapter walls.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCanon DSLR bayonet on the camera side:\u003c\/strong\u003e the body mounts and locks the same way it would onto a lens, with no adapter stack in between.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDistinct from the standard T-thread:\u003c\/strong\u003e Sky-Watcher states plainly that M48 rings are different from T-thread rings, so the two are not interchangeable in this position.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e45 g:\u003c\/strong\u003e light enough that it changes nothing about balance once the camera is on the back.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003e\u003cstrong\u003eOptical \/ Mechanical Design\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eThe adapter sits in the optical train, between the corrector and the sensor, so what it does mechanically has an optical consequence. The M48 thread gives a wider clear bore than a T-thread, which is why Sky-Watcher specifies it for larger-format imaging — the corrected cone from the 0.85x reducer reaches the sensor corners without the adapter throat clipping it. On a T-thread ring the narrower bore becomes the limiting aperture in that same position.\u003c\/p\u003e\n\u003cp\u003eIt is a mechanical part only. There are no electrical contacts on either face, so nothing passes between the telescope and the camera body — no autofocus, no aperture control, no EXIF from the optics. The camera runs in manual, and exposures are started from the body or from a remote release.\u003c\/p\u003e\n\u003cp\u003eSky-Watcher does not publish an optical length or thread pitch figure for this ring. Backfocus in this train is set by the corrector's own published spacing rather than by anything you adjust on the adapter. Send us your telescope and corrector model and we will confirm the spacing you should be hitting.\u003c\/p\u003e\n\n\u003ch3\u003e\u003cstrong\u003eRecommended Uses\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eDeep-sky astrophotography with a Canon DSLR:\u003c\/strong\u003e the prime-focus connection behind a 0.85x reducer\/corrector on an Esprit or ProED refractor.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWider-field imaging:\u003c\/strong\u003e the reducer shortens focal length and the M48 interface carries the resulting larger illuminated field to the sensor.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFull-frame and APS-C Canon bodies:\u003c\/strong\u003e the M48 bore is the one Sky-Watcher specifies where a T-thread would be the restriction.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003e\u003cstrong\u003eCompatibility and Accessory Notes\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eReducers and correctors:\u003c\/strong\u003e Sky-Watcher designates it for any of their 0.85x Focal Reducer\/Correctors.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTelescopes:\u003c\/strong\u003e the Esprit and ProED series, used with their dedicated field correctors.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCollapsible Dobsonians:\u003c\/strong\u003e Sky-Watcher states M48 rings are not suitable for that line.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eNikon bodies:\u003c\/strong\u003e the equivalent ring for Nikon is S20301 — the thread side is the same, the bayonet is not.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eRemote triggering:\u003c\/strong\u003e because the adapter passes no signal, exposures are timed at the camera or through a shutter release cable matched to your body.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003e\u003cstrong\u003eGood to Know Before You Order\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eA T-ring does not substitute:\u003c\/strong\u003e M48 and T-thread are different standards, and the corrector's output is M48.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eThread pitch and length are unpublished:\u003c\/strong\u003e Sky-Watcher lists the standard as M48 without stating pitch or the ring's mechanical length. If you are computing a spacing stack, send us the parts list and we will work through it with you.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCamera bodies are not enumerated:\u003c\/strong\u003e Sky-Watcher specifies the fitment as Canon DSLR rather than naming individual models.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWeight is 45 g:\u003c\/strong\u003e under a pound, which is worth knowing if you are combining it with other small parts in one shipment.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eNothing else is in the box:\u003c\/strong\u003e the vendor lists the adapter itself, with no spacers or additional rings published as included.\u003c\/li\u003e\n\u003c\/ul\u003e\n\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. The M48 face threads onto the corrector by hand and the camera locks onto the bayonet the way a lens does. There is nothing to adjust, align or configure.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eCan I use my existing Canon T-ring instead?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eNot in this position. The 0.85x correctors output M48, and Sky-Watcher notes M48 rings are a different standard from T-thread.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eDoes it work on a Sky-Watcher Dobsonian?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eSky-Watcher states M48 rings are not suitable for the Collapsible Dobsonian line.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eDoes the camera talk to the telescope through it?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eNo. It is a mechanical ring with no electrical contacts, so the camera operates in manual and exposures are triggered at the body or by a remote release.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWhich reducer or corrector does it fit?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eSky-Watcher specifies any of their 0.85x Focal Reducer\/Correctors, on Esprit and ProED telescopes running the dedicated field corrector. Tell us your exact scope and corrector and we will confirm the match before you order.\u003c\/p\u003e\n\n\u003ch3\u003e\u003cstrong\u003eBottom Line\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eThe M48 ring Sky-Watcher specifies for putting a Canon DSLR behind a 0.85x reducer\/corrector on an Esprit or ProED. It is a 45 g mechanical interface with a wider bore than a T-ring, which is exactly what the larger illuminated field behind those correctors needs.\u003c\/p\u003e","brand":"Sky-Watcher","offers":[{"title":"Default Title","offer_id":53896753283183,"sku":"S20300","price":40.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/canon-adapter.jpg?v=1785253508","url":"https:\/\/ontariotelescope.com\/products\/sky-watcher-m48-camera-adapter-for-canon-dslr","provider":"Ontario Telescope and Accessories","version":"1.0","type":"link"}