Just for something to do took some blue sky flats and darks. The clouds soon came back.
Flats were taken at 40X 1600ISO and 1/2000th sec at f/5 with the 300mm lens. Darks were the same exposure.
Made a master flat with sigma combined dark corrected fits.
I then used this master flat to correct the individual flat fits frames.
In theory we should end up with a nice even images.
Here is a full quality image of the corrected flats sigma med combined 800k
http://d1355990.i49.quadrahosting.co.../corrflat1.jpg
Below are a few images taken with the snipping tool in Vista.
1 and 2 the original master flat with histogram and line profile.
3 the corrected sigma stack of corrected flats
4 a single flat image corrected
Yes I am bored.
Bert