This T adaptor ring will fit the Canon EOS range of digital SLR cameras and allow better corrections and wider fields when used with the dedicated reducers than is possible with prime focus imaging. Modern large chip DSLR cameras are allowing extremely wide field images and this adaptor used with the correct reducer/corrector will allow the widest possible fields and corrections.
Note: The M48 type rings are used for larger format imaging. These are different than the standard T-Thread and are not suitable for use on SkyWatcher Collapsible Dobsonians. M48 rings are to be used on the Esprit and ProED series, when using the dedicated field correctors.