RadioFreeCalifornia
celestron 750mm F/6
I bought this on ebay in this condition. The big glass lens on the opening is called a corrector lens, supposedly it has a slightly concave surface that corrects chromatic aberration. This is a Schmidt-Cassegrain design, and is a terrestrial spotting scope. I can see the front lens was cast, not polished and I can't detect any curvature in the lens. I need to put the largest piece on a surface plate and run a tenths indicator over it. I don't think it has any curvature and in any case I'm just going to replace it with a high quality window glass, after which I get to colminate the whole assembly. I hope it's worth the effort. If things work out I get a 750mm F/6 lens that can be used for all kinds of bird hunting... I paid $40 bucks for it so we shall see...
celestron 750mm F/6
I bought this on ebay in this condition. The big glass lens on the opening is called a corrector lens, supposedly it has a slightly concave surface that corrects chromatic aberration. This is a Schmidt-Cassegrain design, and is a terrestrial spotting scope. I can see the front lens was cast, not polished and I can't detect any curvature in the lens. I need to put the largest piece on a surface plate and run a tenths indicator over it. I don't think it has any curvature and in any case I'm just going to replace it with a high quality window glass, after which I get to colminate the whole assembly. I hope it's worth the effort. If things work out I get a 750mm F/6 lens that can be used for all kinds of bird hunting... I paid $40 bucks for it so we shall see...