This is my first time using automatic focusing in EKOS. Typically, I focus once, then never touch it again, and I've not had issues with my flats. But my first imaging session, I did one full set of L at one focus setting, then switched to Red and focused again. I left the focus for G & B at the same setting. Then I did all my flats at my last focus setting, which was what RGB were set to.
If I don't take my flats at the proper focus, I would assume dust motes would not correct out of the image properly?
Hence, the below stretched Luminance image showing uncorrected dust motes.
And then this stretched Green showing no dust motes. Red and Blue also didn't have any.
If you are automating the process of capturing with refocus either for temperature changes or filter changes, then how do you account for the focus setting? Is this information saved somewhere in the image, or can it be appended to the file name?
Also, I took the flats at 20k ADU, which has been typical for me in the past, but as you can see vignetting wasn't fully uncorrected in these images. What's the best way to understand the proper ADU for your flats to correct properly?