31 May 2021: APP 1.083-beta2 has been released ! APP 1.083 stable will follow soon afterwards. It includes a completely new Star Reducer Tool, New File Saver Module, Improved Comet registration and much more, check the release notes here!
Flats that don't remove artifacts?
Tonight I stacked a couple hundred shots of Markarain's chain taken a couple days ago (30sec images, ISO400, in bortle 8 skies, no filters). I have a Stellarvue 102mm telescope, stellarvue field flattener made for this telescope, and I'm using an Ha modified Canon 60D DSLR for the imaging. I am having trouble understanding why the highlighted artifacts don't calibrate out with my flats? I can actually see this artifact in the master flat but for some reason this shows up on this (and other stacked pictures of other targets.) For some reason this one does not get removed in the calibration/registration process and I'm not sure why. Any ideas? I am also attaching a link to the stacked image and calibration files if that helps (in dropbox given their sizes).
Thanks in advance for any insight you could provide. I do see other artifacts that seem to be removed but some do not. Is this perhaps an internal reflection and not a dust mote...does it matter?
Do you also use proper calibration frames to calibrate the flats etc? Thanks for the link, I'll have a look today.
@vincent-mod Yes sir, I use a Master Bias frame I'd taken from some shots perhaps a few weeks ago and I use dark frames each night along with flats shot at the end of the session. I'd included the 3 masters in dropbox.