[Andro (Andrew Bernard)]

Greetings All,

I note that some of the higher end mounts such as the Skywatcher AZ EQ6 GT Dual Goto Mount provide alt-az as well as equatorial functions. Being new to the field of amateur observing, I'd like to ask why one would want alt-az in a high end scope mount? I thought EQ was preferred.

I am aware of field rotation effects. I also understand that virtually all the world's major telescope facilities use Alt-az and field derotators for engineering reasons. But I would be interested to hear from folks why they use Alt-az.

Andrew