Re: Clear Sky Detector

[Stupendous Man <richmond@a188-l009.rit.edu>]

  Michael K. asked:

> Any chance that cloud cover would make for good flat fields?

  On the one hand, the COLOR of clouds is not very different from
the color of stars.  So that's good.

  But on the other hand, the uniformity of pictures of clouds isn't
very good, in my experience.  Even a long exposure with the Mark IV
field tends to leave some of the inherent structure in the clouds
behind.  That's bad.

  Overall, I'd prefer light-box flats.  Or maybe no flats...

                         Michael R