A T-Ring is one of the first accessories you will need if you want to take pictures through a telescope or spotting scope. If you have a Nikon SLR or DSLR camera body, the Celestron Nikon T-Ring is the one for you. In order to use the Nikon T-Ring, remove the lens from your camera, and attach the T-ring in its place, just as you would if you were mounting a lens. The telescope side of the t-ring has threads that will accept a variety of camera adapters, including the Celestron T-Adapter or Tele-Extender. The adapter you choose depends on the type of photography you wish to do