Strange stars

[Lee_P]

Help needed again, expert imagers! After some DeepSkyStacker action, my stars look rather odd -- bright in the middle, then a darker circle, then they get brighter again. I guess I've done something wrong in the processing, but I'm not sure exactly what. Can anyone put me right?

[Zakalwe]

Go to "Stacking Parameters" and select "Cosmetic". Clear the tick box beside "Detect and Clean Hot Pixels" and beside ""Detect and Clean Cold Pixels". See if that makes any difference.

Also, are you in sharp focus?

[Ant]

Zakalwe is spot on, that's exactly the effect that the cosmetic adjustment make to the stars.

The stars do look a little soft to me, so again I agree that focus might be off slightly.

Ant

[Lee_P]

THANK YOU! You were both right about the hot / cold pixels option. Looks like you're right about the focus, too, which is a little frustrating as I used a mask and tried to be oh-so-careful...

[Zakalwe]

Glad that it sorted it. Ever onwards and upwards!

[Lee_P]

How anyone can make progress in astrophotography without the help of Stargazers Lounge is a complete mystery...