T -ring question for mirrorless cameras (1 Viewer)

[MarkBC]

I have been using an old Canon DSLR to digiscope with my Celestron Ultima 100 using a Celestron t-ring for ef-mount cameras. I’m updating to a Canon EOS M50 and I was looking at m-mount t-rings and came across the ones sold on the Telescope Adapter website (T-Ring for Canon EOS "M" Mirrorless Cameras (TEOSM) - TelescopeAdapters). As you can see, these t-rings are cone shaped, not ring shaped like the ones sold by Celestron. An article on the Telescope Adapter website says that the cone or tube shape is necessary for attaching a t-ring to a mirrorless camera because the sensor is much closer to the lens.
I’m not knowledgeable enough about the mechanics of these cameras to know exactly what they mean. The t-ring for m-mount mirrorless cameras on the Celestron website looks a lot like the one I already have for my DSLR. And all the t-rings for m-mount cameras on Amazon also look like a regular t-ring. Am I missing something here?

 

[Ignatius]

If you have been using the old camera successfully with a t-mount adapter ring from celestron, why not just use the new camera also with a t-ring from the same company?
Your question about the differences in flange between dslrs and mlcs is nicely explained here. It mainly has to do with the space needed for the mirror in dslrs having to flip during release.

 

[MarkBC]

If you have been using the old camera successfully with a t-mount adapter ring from celestron, why not just use the new camera also with a t-ring from the same company?
Your question about the differences in flange between dslrs and mlcs is nicely explained here. It mainly has to do with the space needed for the mirror in dslrs having to flip during release.

I just tried the Celestron M-mount T-ring on my Canon EOS M50 and the results were not good. With the camera attached to the Celestron Ultima eyepiece using the new T-ring, there was serious vignetting. About two thirds of the viewfinder were taken up by blackness and the image from the scope was confined to a small circle. Also, I could only get focus when the scope was at about 40x. When I increased or decreased magnification I completely lost the ability to focus.
When I tried this setup with my old Canon Rebel DSLR using the EF-mount T-ring there was was only a small amount of vignetting at the lowest zoom and that disappeared when I began to zooming in. And I could zoom in or out and still get focus.
I will try the T-ring sold by Telescope Adapter and see if I get better results.