I just picked up an old ST8-XME camera for use with my astro club’s 18” observatory reflector (I thought the large pixels would be good match for the scope’s focal length of just over 2000mm). After downloading some drivers I have the camera connected to a PC and running (at least to take some dark frames) but am not sure what the best way to attach it to the scope is. The camera has a 1.25” nose piece on it (first picture). It looks a bit Frankenstein-ish the way it’s attached to the camera but it seems solid enough. This can obviously go into a 1.25” opening, and the second picture shows a 1.25” to 2” adapter attached to it. Is it just this simple or should there be some other sort of intermediate piece in here? The 1.25” to 2” adapter just has a single lock screw and although it seems solid the idea of the whole weight of the camera depending on that makes me a little nervous... Anyway, I have only limited experience with astronomy cameras and thought someone on here might be able to tell me if I’m on the right track here or if I should be doing something differently. Thanks, Brian
Hi Brian, That's not the factory original nose for the camera, and that's an abomination. The "D-block" normally has small socket cap screws (that won't rust) that go into a groove cut in the side of the proper nosepiece. Also, there were variants of an insert with an M-42x0.75 T-thread. Your best bet might be to check ebay or better yet, PreciseParts.com can make you something much better.
Hi Colin, Thanks for the info. So the original nosepiece would presumably have fit more tightly into the D-block and would have a groove near the base to accept the three small screws. I thought at first I might find some other brand of 2" nosepiece that would work (there are lots them listed at Agena Astro and elsewhere) but looking more closely it seems that the aperture of the D-block opening is not 2" but actually very slightly less, so 2" accessories won't fit. I'll poke around eBay and elsewhere and see if I can find something, and may take a look at PreciseParts as well.
