Weird artifacts

@richk67 Hi Richard. That's hard to say without more information. What camera did you use? How many lights of what exposure time, temperature, gain and offset or ISO? Did you use any calibration images? If yes, which ones and the same questions regarding exposure time, temperature, gain and offset or ISO. Which version of APP did you use? Did you modify any of the settings in APP or did you use all default values?

Thanks for a reply. Its 4 nights lights, 57 of them, ranging from 240sec to 600sec. Canon 6D mkii, WO ZS73. Flats (about 20 per night), Darks about 2hrs per night, Bias about 40 per night. Flats and bias taken immediately after run. Darks - I leave camera in a garden shed shooting darks controlled by ASIAir while I sleep 🙂  Temp close to original. Darks same exposure time as lights for that night. Bias 1/4000. Flats about 1/15. ISO 800 for all except final 12 600sec frames at 1600ISO.

Current version of APP. 1.082. I kept most settings the same I think, except went for Winsorized based on number of frames per night (> 10, <20).

I think I may have switched on Dynamic Distortion Correction, margin I did change to 0.1. Interpolation I set to Mitchell as per Sara Wager's tutorial. I may have selected something for final integration screen... Integrate:average, quality. 

Now retrying on defaults.

@richk67 Thanks for the info. Do you get these artifacts also when you only stack lights of one certain exposure time, for instance only the 240 sec lights?

@wvreeven No idea yet. Still integrating on base settings. Very much happier with APP than PI.

@richk67 OK no rush. It takes time to process all images, even with APP. Just let me know as soon as you have an answer tomorrow 🙂

@wvreeven I reprocessed with Normalisation. That seems to have worked. Thanks.

@richk67 Good to see that you got APP to process your data.