Re: (ATM) CCDs on Dobs

Gregory Bajuk (gbajuk@linknet.kitsap.lib.wa.us)
Fri, 25 Aug 1995 21:39:22 -0700 (PDT)

How does a field derotator work? I see it advertised on the Meade 16" LX-200 but no description of operating principles-they are using an alt-az mount. Greg

On Fri, 25 Aug 1995, Jim Houck wrote:

> One problem you might run into is that the field of view will rotate
> relative to the sky. The result is that the stars will follow circles
> centered around the guide star. The rate of rotation will be once per
> day. So nothing will be seen on a short exposure but a ten minute
> exposure will show some trailing near the edges.
>