RE: Post flat processing

[Tom Droege <droege@wwa.com>]

Wow!  I really like seeing this discussion.  I don't think we will be able
to do much about flat fielding other than what we are now doing for the
Mark IIIs.  I have made a pass at using little screens to get a flat field,
but as near as I can tell it is irrelevant.  The sky variations over my
field of view are always much larger than any variations of the flat field.
 So I just use the same old flat field and let Mike's program do what it
can to stratghten out the mess.  I doubt that I ever get what Arne would
call a photometric night. 

At bad locations like mine, 4 sections may not be enough to break up a
field.  I would make them as small as possible, depending only on having
enough stars.  But I just look at the data as it goes by.  So I have not
done any real analysis.   

The Mark IV will be different.  We are building in a flat field box.  We
shall see how well it does.  I think that most of the Mark IVs will end up
at much better locations than mine.  Still I will send one anywhere there
is a good worker who wants to run it.  So we will have to cope with bad
conditions. 

Tom Droege