Recommended Settings for Combining Flats

NOTE: Flats must be dark subtracted. If they have been normalized in a different program then you can uncheck the Normalization option.

Combine Method	Standard Deviation Masking
Pixel Arithmetic	Mean
Smoothing	Uncheck all
Normalization	Check on and try 60%.
Ignoore Block Border	Uncheck
Sigma Value	0.5 to start - Shoot for about 98% usage of each image in the results dialog