[Merlin66 (Ken)]

All the info readily available on the use of flats (to suppress NR and dust bunnies) is applied to surface images and not to applying them to full disk solar images.
Why is still so?
Full disk images also suffer from similar “defects”.....
One very successful method of obtaining solar flats is to use the clear plastic bag over the aperture.
I’ve been trying this method with SER videos (Firecapture) one video of the full solar disk and one with the plastic wrap in place. Using AS3! Latest version V3.1.4. A master flat can be made as a tiff and then applied during the stacking of the solar disk. Sounds pretty straight forward.....
(Seems to work well with surface images)
After three days of trials, I found a major problem.
Summary: For full disk flats to work, the master flat image must be registered 100% with the solar disk stack/ individual frames. There’s no way I can find to actually do this! It really comes down to having ABSOLUTELY PERFECT Polar alignment with NO drift between the flat image and the solar disk stack/ individual frames.
Obviously my alignment wasn’t 100%
This is not a major problem when normally imaging, AS3! will make the necessary minor corrections to give a quality outcome. The problem is how to register the flat to the individual frames ( the flat is applied to each frame during the stacking process). I don’t know the answer, but I do know if you re-align the mount with some accuracy there is enough registration to remove NR etc.
I have some sample images showing the results. Still not perfect, but certainly an improvement in the suppression of NR.
If anyone has found a better more robust solution I’d love to hear about it.

Onwards and upwards.