This sturdy aluminum T-Adapter is the accessory of choice if you’d like to attach an SLR or DSLR camera to the smaller rear cell threads of a Celestron NexStar 4SE telescope or C90 spotting scope for prime focus photography. To get started, you’ll need the appropriate T-Ring for your camera body (#93402 for Nikon & #93419 for Canon EOS). Remove the lens from your camera and attach the T-ring in its place. Since the T-ring is camera-brand specific, it will snap right on just like a lens. Next, remove any accessories from the rear cell of your telescope. Screw the Celestron NexStar 4SE T-Adapter onto the rear cell threads until secure. Now, thread the T-ring & camera onto the T-Adapter. That’s all there is to it. The camera is now using your telescope as a telephoto lens. Prime focus photography is popular for short exposure images of terrestrial objects as well as celestial objects like the Moon.