Doughnut stars after stacking ?

[Garethr]

Hi all

Help needed again !!

I seem to end up with Doughnut stars after stacking what I think are reasonable subs " given my location and kit".

Using DSS on default settings and discarding anything below about 70% I am still getting horrible doughnuts in the stars.

Any suggestions would be greatly appreciated  

Attached is a tiff of an average sub anything below this is discarded, using flats, darks and bias keeping an eye on the histogram but still seem to end up with the same result what am I doing wrong?

Any suggestions welcome

JPEG to follow

Gareth 

L_0017.CR2

[Garethr]

JPEG

stacked and RGB aligned  nowt else

What am I doing wrong please 

 

[Garethr]

And a JPEG of one of the subs 

 

[Marky1973]

Hi Gareth.

When I had trouble with donut stars, the solution I found was to uncheck the Hot pixel removal settings in the cosmetic tab in the Stacking Settings.

There is also a hot pixel setting in the DARKS tab, but I can't remember if that needs unchecking as well. Try the Cosmetic tab first, hopefully that will work.

Cheers

Mark

 

 

[Owmuchonomy]

The stacked file has a ring to me of poor flats. Try stacking without flats to see if that removes your donuts.

[Garethr]

Cheers guys will try both and report back. 

 

Gareth 

[Garethr]

You guys are heroes.

Tried without the flats which did improve the stars but then tried unchecking the hot pixel boxes and bang

Problem solved.

New flats taken and re processed now have nice stars and lots of fuzzies.

Many thanks.

Gareth