Posted by Lawrence Regira (209.214.155.107) on January 03, 2003 at 21:39:06:
I had my 12.5 inch mirror refigured by Steve in June but unfortunately I have not yet mounted it back on the scope. I still have a few things I want to do to it. I purchased a low profile focuser from MoonLite Telescope Accessories and a CatsEye collimator this Christmas from Jim Fly. I want to move the focuser further up the tube. I also will need to extend the old tube. I have an article in an old 1992 issue of Sky and Telescope where a tube is extended using 1/8 inch masonite. I think when I do finally get my scope up and running it will perform better with this setup. Steve was surprised that I was satisfied with my old mirror because he found it was overcorrected in the middle areas and undercorrected towards the edge. I think due to the placement of the secondary in the original Cave setup, the outer inch or so of the mirror was not being intercepted by the 2.6 inch secondary in its original location. I read an online article stating that you should be able to see the entire mirror and then some when you view your secondary through the eyepiece holder. I know in the old setup this was not so. So, basically I was working with about a 10 inch overcorrected mirror all those years. I am also thinking about painting the tube black. I was reading on Carl Zambuto's forum where he thought a black tube was best. I sure do a lot of reading!
Lawrence Regira