Focus issue or stacking issue?

[PeterCPC]

I use AstroPixel Processor. Blows DSS out of the water. Not free. You can rent or buy.

[Seelive]

Try changing the alignment method.  DSS usually defaults to Automatic which with 700+ detected stars will result in Bicubic being selected.  I've occasionally have had similar results of aligned stars in most of the image but strange effects in some areas.  Select either Bisquared or Bilinear instead. 

 

[Pryce]

13 hours ago, Seelive said:

Select either Bisquared or Bilinear instead. 

Thanks!  I'll definitely try that once I get home from this session! 

[Pryce]

I finally figured it out!   Detect and clean remaining hot pixels was the culprit!   Aaaah!   Finally some nice and round stars! 😁

[Pryce]

Here's a quick and dirty edit.

just over 10 hours of data in this one, stretched and slight curves adjustment, set RGB levels and a modest noise reduction in Topaz DeNoise

[PeterCPC]

Glad you got it sorted.

[ollypenrice]

On 14/01/2021 at 18:13, Pryce said:

That's a good idea!   

Anyone in perticular I should give a go?

 

AstroArt.  The price is reasonable and the recent gradient removal tools also work. I do all my stacking and calibrating in AA. It is fast, logical, well laid out and has lots of extras if you need them.

APP also seems good. I have never got on with DSS but it would be mean to complain, given the price! 

Olly

Edited January 16, 2021 by ollypenrice

[Seelive]

2 hours ago, Pryce said:

I finally figured it out!   Detect and clean remaining hot pixels was the culprit!   Aaaah!   Finally some nice and round stars! 😁

🖒

[kirkster501]

What are your calibration frames like?  Many don't but you should always check them all individually as well, you should blink test or otherwise look at each individual flat/bias/dark frame and check it is ok.  If a duff flat/bias/dark creeps in you can wreck the resultant master calibration frame which then in turn can wreck your master image.

What image integration are you using?

I use PixInsight for all pre-processing.  It is incredibly powerful.  Download a trial version.  It is not cheap but it is masterful at what it can do.