Re: TN 76 finished (for now)

[<aah@nofs.navy.mil>]

Oh, yes, a couple of other noise sources: dark subtraction
and flatfielding.  The master dark was not formed from
many frames and so has significant noise.  The flatfield
was formed from 19 frames, but each frame had ~1200 ADU
signal level.  At 2.5e-/ADU, that means about 3000 e-/pixel.
Since 1mmag requires 1M e- so that the noise in the flat
is less than the noise in the star, your flats are
not good enough.
  Bottom line:  don't worry about the noise floor until
the images are taken specifically to get the highest
photometric quality.
Arne