Celestron’s Barlow (X2) T-Adapter 1.25″ allows you to connect your camera to your telescope, but with the bonus of a built in Barlow! This particular Barlow effectively doubles the existing magnification and focal length of the telescope with a camera. Your camera will need to already have a brand specific T-Ring (Canon or Nikon)to attach to this adapter. It’s also possible to use this Barlow for a direct observation, with an eyepiece attached to it, instead of a camera. Here is a more detailed review I wrote about the Celestron Barlow (x2) T-Adapter.
Some care should be exercised when securing your expensive camera to your telescope this way, since it will be held in place by only a small screw. Especially when attached to the telescope for long periods of time, where temperature drops could cause the metal screw to contract. Because you are generally attaching a DSLR camera that works best with a lens of 2″ diameter or more, you may experience some vignetting (especially when used with telescopes that have a short focal length), but the magnification you gain is worth it.
To attach your camera to your telescope with this product:
1) Attach your camera (with the appropriate T-Ring already on) to the Barlow T-Adapter
2) Attach the assembly to the 1.25″ visual back/eyepiece holder of your telescope (after removing the diagonal and eyepiece).
3) Begin using your telescope as a very large camera lens.