Help with odd artifacts in amages

[pmrid (Peter)]

I've been working my way into OSC imaging using different SharpStar 94EDPH and 61EDPH APO refractors and Optalong L-Enhance and L-Extreme filters.

I'm finding these odd artifacts in my images and can't put my finger on a cause.

They are basically rings around star cores - and they are across the whole image although more prononced in the edges and corners. I've encountered them using Flattener/Reducers and without.

I am using ZWO filter cartriges/drawers and I've tried moving them up and down the backfocus 55mm space but wth no difference.

I focus with ASIair Plus and with a Bahtinov mask with no difference.

Exposures have been 180and 300 seconds with no appreciable differnce.

A couple of extreme crops attached as examples.


Any thoughts?

[ronson]

Hi Peter,

What camera are you using and what camera settings in Asiair?

What software are you using to develop the FITS files?

[pmrid (Peter)]

Originally Posted by ronson

Hi Peter,

What camera are you using and what camera settings in Asiair?

What software are you using to develop the FITS files?

Using both ASI533MC Pro and ASI071MC Pro CDs with gain set at their Unity Gain points - 94 in each case. Stacked in DSS and saved as 32 bit Tiff images processed in PS6.

[RobC (Rob)]

Morning Peter,

They look like stacking artifacts to me. Suggest you restack in PixInsight.

Cheers

Rob

[pmrid (Peter)]

Originally Posted by RobC

Morning Peter,

They look like stacking artifacts to me. Suggest you restack in PixInsight.

Cheers

Rob

Thanks Rob. I’m going to give Siril a whirl. I’m a PI luddite I’m embarassed to admit.

[Nikolas (Nik)]

Turn off cosmetic correction in the DSS settings those donuts are a tell tale sign they are turned on

[pmrid (Peter)]

Originally Posted by Nikolas

Turn off cosmetic correction in the DSS settings those donuts are a tell tale sign they are turned on

Thanks for that tip. Will check that ASAP.