I’m very new to most of this, and am learning the ins and outs. I’ve mostly used Siril’s osc script to process images from darks, lights, biases, and flats in folders. I’ve tended to use background extraction and manual colour calibration to get around parts that felt “weird”, but thought I’d take a deeper look into what’s actually going on.
I’m attaching screen captures of my stacked calibration frames (in Siril’s histogram mode). Do these look ok? I see a semi-interesting pattern of the flat, and a very strange polygon for the dark and bias. Looking at it, I’m almost certain that it’s the lens cap that’s letting in light, so I’ve been feeding it junk darks and biases… or is this sort of pattern expected? To takes darks, I simply put the lens cap on, and take pictures with the same settings as the lights. For biases, I put the lens cap on and set the shutter speed to 1/8000s (the max on my camera - in this case, the Sony A7R iv).
Any input is appreciated.