Re: Bits and pieces

[Tom Droege <tdroege2@earthlink.net>]

OK, I do save all flat/dark sets.  So this is not a problem.  Well, it is a 
problem for the old data since my log book and filing system are not so 
good.  But they will get better over time.

How do you get a master dark from the object images?  I have assumed that 
you can only get flats from the object images???  Also you can't get a 
light box flat from the data, and at least I have been convinced that there 
are problems with a sky flat due to the gradient in the sky.  I suppose 
that you can get a combination sky_flat/dark from the object images??

Tom Droege

At 01:44 PM 6/3/03 -0400, you wrote:
>Even before one gets to the photometry, there could be differences
>if one has not saved the master dark and master flat frames used
>in the original processing.   One can recreate the master dark
>and flat from the raw images, but that will take several minutes.
>
>                                         Michael