Re: ATM alt-alt vs. Dob-

[Adrián Toledano <atoledan@prodigy.net.mx>]

I dont´t remember very well, but I think I read it somewhere, that the
russian big telescopes are mounted in alt-az mounts. The reason was as far I
can recall, it was a lot cheaper this way than making equaorial mounts.

For tracking, they use (used?) to motors controlled by a computer that keeps
the telescope pointing correctly, they also have an aditional motor where
the camera was attached, this motor rotated the camera/film holder to
balance the efect of field rotation on alt-az mounts.

Again, I THINK I read this somewhere, so maybe someone can add more light in
the subject.

just my two cents

Adrian