Eyepiece and telescope pairing
Connecting a camera to the Orion SkyQuest XT4.5 Classic Dobsonian
The exact thread or barrel that lets a camera reach prime focus on the Orion SkyQuest XT4.5 Classic Dobsonian, and the adapter that makes it work.
- Telescope interface
- 1.25 in focuser (no rear-cell thread); a T-adapter noses into the focuser
- Adapter needed
- a 1.25 in prime-focus (nosepiece) T-adapter, plus a camera-brand T-ring
- Camera-side thread
- T-thread (M42 x 0.75), via a camera-brand T-ring
- Prime-focus focal length
- 900 mm (f/7.9)
Not for prime-focus imaging. The Orion SkyQuest XT4.5 Classic Dobsonian reaches a camera only through its 1.25 in focuser with a nosepiece T-adapter, but a manual Dobsonian base does not track, so long-exposure prime focus is impractical. It is a visual and short-exposure lunar scope.
A camera reaches a telescope's prime focus through a T-adapter that matches the telescope's interface on one side and the standard T-thread, M42 x 0.75, on the other. A camera-brand T-ring then bayonets to the body.
Unlike a Schmidt-Cassegrain, this design has no threaded rear cell, so the camera mounts through the focuser drawtube. Check that the focuser has enough inward travel to reach focus with the mirror or sensor where a camera sits.
The adapter to buy
Shop a 1.25 in prime-focus (nosepiece) T-adapter on AmazonaffiliateFind a 1.25 in prime-focus (nosepiece) T-adapter on eBayaffiliateShop Camera-brand T-ring (M42 x 0.75) on AmazonaffiliateFind Camera-brand T-ring (M42 x 0.75) on eBayaffiliate