Hello all,
I am a relatively new PI user, so I apologize if I am missing something obvious related to this question. I have acquired ~100 DSLR images ranging in length from ~2 minutes to 10 minutes, ISO 1600 to ISO 12800 of the Iris nebula. None of the images appear saturated (though some of the stars are close). I am using a Canon EOS 6D, Edge C11/CGEM DX, F7 Focal Reducer, Lodestar OAG, Nebulosity, dithering, and PHD2 (and generally have gotten tracking errors <1"). I have generated a SuperBias using 60 bias frames, and a 20 frame flat; because I am dithering, I skipped darks.
The problem: The first 60 frame Sn and Qn integrations with linear fit looked pretty good (though still with fine grain/small scale noise). However, when I added more frames, suddenly a patch of the image with very clearly defined edges developed a red color. I searched the individual frames using blink, but don't see any evidence of this red patch in the individual frames.
I include a PNG of the image below with just an ABE and simple STF applied; the red patch is in the lower right. Is this a statistical weirdness, am I using something incorrectly, or are my frames just subtly goofed?
Thanks in advance for any thoughts on the matter,
Scott
PS: I can place the original frames on dropbox, or the single FIT file, if desired.
