I have found one mis-feature with BatchPreprocessing. It affects, at the very least, flats, and probably lights.
If you add in image files that have the same *filenames* (from separate folders, e.g. folders by date), the calibration step will write the calibrated images to a new folder. However, if you have a file named e.g. "2012-12-29/flat-Blue-1x1-30C-001.fit" and one named "2013-01-01/flat-Blue-1x1-30C-001.fit" these both gets written as "calibrated/flat/flat-Blue-1x1-30C-001.fit" into the destination folder. Then, when the integrated master is created, such images get used multiple times.
What I saw in my case was 26 images in 2012-12-29 and another 101 images in 2013-01-01 (I have an EL panel, so getting a good number of flats is not much of an issue)... So I ended up with 101 images in the "calibrated/flat" folder, while ImageIntegration reported that it had used 127 images. Looking carefully at the log, the images with sequence numbers 001 through 026 had each been used twice.
I have not checked if this also happens with lights, but I assume it will if they otherwise are the same. Bias and dark frames appear not to be a problem as they are not being calibrated (even, for darks, when "Optimize dark frames" are enabled...?).
I have been going maybe a bit overboard (?), making my masters from integrations of 127 raw frames (bias, 90 minute darks and flats for each filter) -- the only really time consuming ones to acquire being the darks, which must be done over multiple nights.
Thorsten
