Poor flats results - Forums

Topic starter

Dec 21, 2021

Hello,
I think I must be the worst at taking flats with hyperstar. Bright spots in the middle and bright gradients outward portion. Are you supposed to go with .36 for the average background number talked about in some discussions? Basically, lost at this point..
thx
Charles

Rick Veregin

Dec 21, 2021

Could you provide more detail on your setup, camera type (CMOS, CCD, DSLR, mono or color), image size (full frame, APS-C?). The basics are not any different than for any other flats–are your other flats okay without hyperstar? But if you provide details, I or others can be more specific to your situation on the basics. There are some special considerations for hyperstar. If you saw my previous post just below this at F2 the light box can be a problem with a DSLR cutting into the light cone, might even be an issue with some astro CCD and CMOS too, not sure they all considered the wide F2 light cone in their design. Also, the dew shield if you have one can be problematic, I found I had to spread it really wide to not cause vignetting because your FOV is so much larger at f2.
Rick Veregin