One of the first items you'll need to use a telescope or spotting scope to take photos is a T-Ring. The Celestron EOS M-Mount T-Ring is the best option if you own a Canon EOS mirrorless camera body. How to Use Put the M-Mount T-Ring on your Canon mirrorless camera to use this T-Ring. Align the T-Ring with your camera's lens mount, much like you would when replacing a lens. Turn it until you hear a click, then push it in. A strong bayonet flange on the T-Ring locks for a tight fit. You can connect your telescope once the T-Ring has been connected to your camera. The threads on the telescope side of the T-Ring are compatible with a number of camera adapters, including the Celestron T-Adapter. The type of photography you want to do will determine the adapter you select. Body The 42mm T-ring for the Canon M-Mount is made of black anodized machined aluminium. For the maximum contrast, the inside surfaces are blackened and glare-threaded. A ribbed surface on the T-Ring provides a firm grip for threading or unthreading. M42 x 0.75 (T-Thread) camera adapters are compatible with the Canon M-Mount 42mm T-Ring. Terrestrial and Celestial imaging To transform your telescope or spotting scope into a powerful telephoto lens, combine your T-Ring with a Celestron T-Adapter. Use these adapters with your M-Mount T-Ring, depending on the optics you have: * Please reference specific product pages for compatibility Optics T-Adapter to pair with the M-Mount Spotting Scope* Universal T-Adapter - 1.25" Schmidt-Cassegrain telescope T-Adapter for Schmidt-Cassegrain Telescopes Refractor telescope Universal T-Adapter - 1.25" Newtonian Reflector telescope Universal Barlow and T-Adapter - 1.25" NexStar 4SE T-Adapter, NexStar 4SE EdgeHD (8") T-Adapter, (EdgeHD 8) EdgeHD (9.25", 11", 14") T-Adapter, (EdgeHD 9.25, 11 & 14) - T-Ring attaches to M-mount Canon mirrorless camera bodies - Works with Celestron T-Adapters - 42mm female diameter thread - Sturdy bayonet flange locks for a secure fit - 2 year warranty This T-Ring fits EOS M-mount mirrorless cameras only. It will not work with other Canon camera bodies like the EOS RF-mount or EOS EF-mount model cameras without adding a Canon adapter to convert those cameras to M-mount. Thread: M42-0.75 Camera mount: Canon M-mount for mirrorless cameras Construction: Aluminium black anodized Outside Diameter: 65mm (2.56") Thickness from flange: 10mm (0.39") Weight: 1.76 oz (50 g) Note: Telescope is for illustrative purposes only and not included.