I have a ZWO ASI 294 mono with the Zwo filterwheel and OAG. The filters LRGB are Chroma 50mm unmoumted and the HA is Baader.
The reason I have a Baader Ha is simply that in Europe there is no stock anywhere and the lead time is around a month even more.
Doing the flats for all the filters is fine except for the HA. I have tried everything I can think of but the result is always the same and I do not see that issue on the images taken at night.
It would seem that only whiles doing the flats the problem arises.
I have had to upload the image to Astrobin so there is enough details showing what I mean.
Has anyone experienced this issue before?
Thanks for looking.