Modern catadioptric telescopes as camera lenses?

[CuriousOne]

Hello.

There are a lot of cheap catadioptric telescopes available today, with quite good specs. For example, 450/4 one costs around $120 brand new. Same specced mirror lens costs at least 5x times more used. So are there any caveats or problems (besides need of adapter) to use these telescopes as camera lenses?

[Himself]

Cheap glass, low resolution, etc.

[480sparky]

Lack of aperture ring.

Doughnut-shaped bokeh.

Low contrast.

But you can get usable images from a cat telescope.



Taken with a Celestron CPC 2000mm f/8.

[CuriousOne]

Nice pic!

what was the approx. distance to bird?

2000mm is great, but F8 does not

1000mm F2.8 would be much better

[marcusBMG]

Perhaps "digiscoping" with a good spotting scope is a better option?
I recently acquired an Opticron. I ordered a connection ring to use with a Panasonic LX5 from China, it arrived today but its the wrong one. Panasonic, for reasons known only to themselves, changed the thread pitch from the LX3 to the LX5 on the thread on the lens
I'm using M42 extension tubes and a deglassed 3x TC to make the connections, the scope has an M42 thread by the ep. The typical digiscoping technique seems to be to photograph the image produced by the scope ep with the camera lens, which is why small sensor cameras are used a lot. The exit pupil of the dedicated digiscoping ep seems to be around 10mm. I did try a few pics directly through the scope but the focussing range I was able to achieve was only 2-10m (and of course the image in the camera vf is inverted and up-side-down - very disorientating).
I'll post a few results as and when.