How do I connect a single-lens reflex (SLR) camera to my telescope?
To connect an SLR camera to your telescope, you’ll need two accessories: a T-ring and a T-adapter. The T-adapter system is a worldwide standard 42mm thread to connect cameras to other devices. T-adapter system for SLR cameras. A T-adapter attaches to the scope and a T-ring attaches to your SLR camera. A T-adapter with a 1-1/4” eyepiece barrel is very versatile and will slip into the eyepiece drawtube of most telescopes. Other types of T-adapters with threads are specific to certain types of scopes. (Specialized accessories like a radial guider or tele-extender have T-threads that take T-rings, so they act like specialized T-adapters.) The threads on the T-adapter will fit into all T-rings. Since each brand of camera has its own specific thread size or bayonet type, you need to get the proper T-ring. Thus Canon has its T-rings (two of them); Nikon has its own T-rings; Minolta has their own specific rings, and so on. Any camera store will have T-rings for most popular makes. First, remove the visual accessories you are using – eyepiece, diagonal, visual back. The either screw on or insert the correct T-adapter for your scope and the type of photography you want to do. Example: to use the T-adapter with the 1-1/4” barrel, remove your SLR's lens and attach the T-ring to your camera, then the T-ring to the T-adapter and slide the 1-1/4” barrel into your eyepiece holder. Add a shutter release and the camera is now ready for prime-focus photography. Your telescope acts as a platform and can be used to provide tracking if the scope has been polar aligned. Tracking may not be needed for very short exposures of the sun, moon and planets. IMPORTANT NOTE: For some Newtonian models, the focal plane of the telescope may not be far enough from the tube to allow you to focus with the T-adapter/camera setup you are using. Try using a T-adapter with a built-in Barlow lens (with the lens at the forward end), such as Celestron’s #93640 to extend the focal plane to reach your camera’s imaging plane. Another way that will achieve infinity focus with almost any Newtonian or other telescope is eyepiece projection directly into your camera with Celestron’s #93230 8-24mm zoom eyepiece. Since the eyepiece has T-threads under the eyecup, simply thread it into your T-ring and then attach to your camera and put the assembly into your scope’s eyepiece drawtube.
Created On: Dec 01 2008 12:29 PM