Artifacts after DSLR Workflow

[tsaban]

Hi,

I managed to process my recent DSLR subs exactly (I hope so) according to the guidelines found in

http://pixinsight.com/forum/index.php?topic=2570.0 and the video tutorials (normalization: additive+scaling, rejection1: Linear fit clipping,... as in the example). The stars seem to be stacked quite nicely but I see some artifacts when auto stretch the image with the screen transfer function in low s/n areas as can be seen below:



Interestingly I don't get these (in PixInsight with the screen transfer function) when I use ImagesPlus fro the calibration and stacking.

One fact: The subs are far from being perfect, they show quite a variation in background brightness.

Does anyone have a hint what I did wrong?

Thanks!

Tahir Saban

[pfile]

these are hot pixels that were not rejected by your stacking algorithm. what algorithm did you use?

since they are streaking like that they should be relatively easy to reject.

[tsaban]

Thanks pfile. I have solved the problem by now.
I had used the linear fit algorithm suggested in the example.

Thanks
Tahir

[astropixel]

I had the same problem and used Windsorised clipping, which was better, but proper dithering eliminates these trailing artifacts, or so I have found.