Quote Originally Posted by David A. Goldfarb View Post
Were/are these the solid cats? I've always heard good things about these. They also had a fast mirror lens, like 450mm/f:4.5 if I remember, and I think it used plastic in some then-innovative way. Did you ever try that one?
Dear David,

Yes, they're solid cats. I used to have a 680/6.8 prototype too but gave it to a friend. He died and I believe another friend inherited it. The 450/4.5 was probably not available commercially (there are different views about this) and did I believe use plasric, but the 600/8 and 800/11 solid cats used glass, not plastic, for the light path.