Large Dob (20"+) For Astrophotography?Posted By Tyler Allred |
Hi Mike. I'll take a shot at answering this question. I have only seen a few imagers who use large dobs... Al Kelly is the main one who comes to mind. The problems with big dobs are pretty tough. First, you would be working with a long focal length, so any error in tracking is magnified. Second, the things are like a big sail in the wind. Even the slightest breeze would have them shaking like a leaf. Third, the field rotation is another problem, but it can be dealt with using a derotator, assuming all the other problems were solved. I think that most imagers using a big dob have them mounted on an eq platform, but most of those platforms are not really smooth. I have seen some wonderful images taken with big dobs on split ring mounts. If you decide to get serious about spending cash, I know a guy who builds world class split ring mounts for dobs. He mostly uses his for scientific work, but occasionally takes a break and takes "pretty pictures" (as he calls them). 
Each of his mounts is custom made... nothing is mass produced. If you are interested, send me a private message and I can send you contact info. I think his mounts probably start at about the cost of a Paramount, and go up from there. That is my 2-cents worth.
Cheers,
Tyler
Each of his mounts is custom made... nothing is mass produced. If you are interested, send me a private message and I can send you contact info. I think his mounts probably start at about the cost of a Paramount, and go up from there. That is my 2-cents worth.Cheers,
Tyler
