I’ve been using Siril for all of 5 days now (and that’s the full extent of my astro image processing experience, so this is that kind of novice question).
I have gotten results using Siril that made me pretty happy, but I wanted to combine subs from two different nights. I have separate lights (70 one night, 100 the next), flats (~30 each) and darks (20 each) for each night, and one set of biases. I read that sirilic was the way to stack the two sets of images together (please correct me if I can and/or should be able to do that directly in Siril).
When I stack using sirilic, I get a “hole” in the image:
I have seen this hole before - in some test exposures an earlier night when I had not taken any flats (and also in a picture from someone else with a Canon 700D somewhere on the web). I can reproduce the same artifact in Siril by processing the same data not including flats. With Siril and flats the issue is corrected.
I’ve run sirilic several times, and am quite sure I put the flats in the correct place.
which version of Siril and Sirilic are you using?
Can you provide me with the two script files generated by sirilic for analysis (sirilic-part1.ssf and sirilic-part2.ssf in the “… / script” folder)? as well as the configuration file “C: / users /…/. sirilic2_rc”
Thanks for responding! And, even more, thanks for writing the tool. Siril and Sirilic are just what I need to get a foothold in the hobby. As a beginner, the main thing that will get me going to the point where I am able to delve into how things really work is having tools that let me get nice results without knowing much yet about how things work - tools just like Siril and Sirilic that have rational defaults.
I am using Sirilic v1.12.8 and Siril 0.99.6 (I started with 0.9.12, had the same results). Windows 10
I analyzed the generated scripts and I did not see any problem. Are you sure you have put the “flats” files associated with each session and not inverted.
A note: by analyzing the script, I saw that you stacked the offsets but afterwards you do not use the master offset?
Here is a screenshot of the Process panel. I did not do anything to alter the scripts generated by Sirilic (nowhere near that knowledgeable or brave yet!). From this I would expect the flat master to be applied to final .fits file being piped to Siril.
(Thanks for the explanation you posted while I was typing!)
Oops - I see now that I misread what you said (still getting used to the terminology). I was thinking Offset referred to Flats, when it is actually what I have as Bias (which makes more sense).
As I analyzed the script, I noticed that you stacked each session. It is not useful in my opinion and it slows down the processing.
You can uncheck ‘intermediate stacking’ in the project properties (Menu-> Project-> Edit Properties):
Thanks - I was still working on understanding the effect of intermediate stacking.
For your 1000D Process:
Is subtracting the Offset separately from the Lights and the Darks different from leaving the Darks alone and then subtracting them from the Lights? It seems to be algebraically equivalent, but I might be missing something.
indeed with my CMOS sensor (Asi183), I no longer subtract the offset of my lights because I leave the offset in my darks. It’s equivalent for me but I’m not a specialist
Sounds reasonable. I’m also willing to bet beer that I would not be able to tell the difference between the two ways of doing it, even if an expert said one way was better than the other.
