Good afternoon,
I've been trying to track down what seemed to be a vignetting problem (ATIK383L/TMB92ssf5/5, 2"narrowband filters). However, in experimenting with BatchPreprocessing, it seems that something is going on with the "optimize dark frames" option. As a test, with "optimize dark frames" checked, I input three each, all the same temp, 1800s OIII frames (actually I had two of these, and copied one to make three), I took matching 1800s darks, OIII flat subs, flat darks of the same duration as the flat subs, and bias frames. BPP correctly chose the 17 second flat darks to match the flat subs, and the 1800s dark subs to match the lights. BPP really didn't "need" to scale the darks, since temp and time matched, but it did. However, the master light frame looked vignetted (i use a flip flat and am quite sure I made good flats). Now,I could flatten out the master light with DBE, but I wasn't sure if I was correcting a gradient issue or masking poor calibration. I then reran the process with "optimize dark frames" UNchecked, and the master light that came out looked nice and flat, and correctly calibrated. I'd be appreciative of someone taking a look at the two master light versions. The only other clue I could find, was that when optimization was checked, while I would have expected the scaling factors to be close to 1, they were far from that, and I wasn't sure why.
I'd be happy to send three each of the various subframe types if necessary, but am unsure of how (is there an easy way to pass along a zip file containing the subs?) For now, I'll just attached the "optimized" master light to this post, and the unoptimized one to the next post.
Thanks in advance for helping.
Regards,
Bob Hertel
