Siril & Sirilic producing different images from identical data.

[Cassiopeia1]

Hey everyone,

First time poster here.
Short version: Sirilic produces a very different image than Siril does from the same exact set of data, same lights, darks, biases and flats, from the same session....

 

I stack my files using Siril but tried Sirilic due to its reputation for making multi-session stacking easier. It turned out very badly. The image was washed out green with very little data to be stretched.

As an experiment, I took a single night session and did the OSC preprocessing script in Siril and took the same night session and ran it as a single session (not multi)in Sirilic. The results were complete different from one another as can be seen in the two attached images.

Both are shown in Autostretch viewing mode. Somehow Sirilic treated the data differently than Siril did(more precisely, it produced a script very different to Siril's OSC-Preprocessing script). Sirilic Script is attached below, though I can't see anything in it that would produce such a subpar output.

To be clear, it’s not that the data needs to just be stretched in Sirilic, it’s that the starting point is not the same as in Siril using the same data and in fact after much stretching etc, the data doesn’t even seem to be there. It’s like something akin to a single image rather than a stack.
I have tried adjusting several parameters in Sirilic but nothing has made any improvement to the output image that auto-loads in Siril
If anyone has any suggestions, I'd really appreciate it
Many thanks in advance

[TiffsAndAstro]

I never managed to get sirilic to work for multi session, even after watching deep sky Astros tutorial on YouTube.

Not tried it since I upgraded my dslr to an osc. 

Maybe watch his video, it might help?

I've been "just about" getting away with processing each night in siril but then taking the pp_lights each session creates in "process" directory and making a sequence from them after conversion. It's a bit clunky but works ok I think.

[Mr Green]

Welcome to the forum.

I don't have any experience with Sirilic and tend to only use Siril for background extraction and photometric colour calibration.

Have you tried Deep Sky Stacker out of interest? Processing projects that span over multiple nights is extremely easy and because of this, I've not tried stacking with any other method.

There are various tutorials online and it's free.

 

[bottletopburly]

Have you tried setting the parameters in sirilic the same as Siril script ? , I do like sirilic but at the moment can’t get it too work, awaiting the next version to see if they fix the bug , 

[Elp]

If you read the sirilic script you can replicate the process manually in Siril, the -tags show what settings/checkboxes have been selected.

Multi session stacking in Siril is easy, you simply calibrate all your lights per session and can export them out as individual images in the second "sequence" tab. Then when you're ready to stack multiple sessions you just load every single calibrated light in the first tab, the first set of data will be what others sessions stack to (if you've used different cameras or optics they'll be scaled to fit for example) make sure symbolic link is checked, then register tab, and stack tab. Done.

Before you use a script you should know what the script is doing by reading through the programming of it and understanding how it works, instruction by instruction. I've never used Sirilic but can read the above example and know what it's doing.

Manually stacking in Siril isn't difficult, I do it every session and it becomes clockwork, almost autopilot when I use it.

[Pompey Monkey]

Your "duff" image seems to have only an 8-bit colour depth, even though the PNG has 32 bits of range.

I have no idea about how your particular software works, but is there an option to set bit-depth (you want 32!) when saving the file?

[Elp]

Siril by default I think saves as 32 bit but if the input is less, you won't magically get back to 32 bit.

[Pompey Monkey]

Did you feed the raw files into sirilic, or the jpegs?

[Cassiopeia1]

31 minutes ago, Pompey Monkey said:

Did you feed the raw files into sirilic, or the jpegs?

Sorry for the delay to everyone, I am working at the minute but will answer more extensively in an hour or so.
I feed only RAW lights, darks, biases and flats into Sirilic. I've a reasonable idea from looking at the script what it is attempting to do alright as I have practiced some manual registration, calibration and stacking in Siril.
The key confusion here is why Sirilic outputs such different a result when fed identical data as Siril. I literally did one right after the other from the same set of lights and calib frames. 
Siril is fantastic and I find it very straightforward. 
I went into the OSC-preprocessing Siril script and compared every line to the Sirilic script. I tried changing some parameters which were different such as no RGB equalisation or Cosmetic Correction in the default Sirilic but none of it made any improvement.
I even just stacked the lights in Sirilic to see if there was a problem in the Offset and Darks part or the process but that didn't help either. 
Thanks to everyone for the replies. I will be back on here soon

[Cassiopeia1]

By the way, here is the result when I just stacked in Siril. Pretty happy with it for a beginner image to be honest. Lots to improve of course.

Just wish I could have done it more conveniently in Sirilic as it was a 2 night session.

I'm tracked but unguided so just 30 sec subs for a total of 3 hours.

150PDS on EQ5-pro.

Lumix G7 M 4/3 camera

 

 

[TiffsAndAstro]

2 hours ago, Mr Green said:

Welcome to the forum.

I don't have any experience with Sirilic and tend to only use Siril for background extraction and photometric colour calibration.

Have you tried Deep Sky Stacker out of interest? Processing projects that span over multiple nights is extremely easy and because of this, I've not tried stacking with any other method.

There are various tutorials online and it's free.

 

Last time I tried dss I had to use a dummy file in tab one so other tabs worked. Seemed a bit iffy.

[TiffsAndAstro]

13 minutes ago, Cassiopeia1 said:

By the way, here is the result when I just stacked in Siril. Pretty happy with it for a beginner image to be honest. Lots to improve of course.

Just wish I could have done it more conveniently in Sirilic as it was a 2 night session.

I'm tracked but unguided so just 30 sec subs for a total of 3 hours.

150PDS on EQ5-pro.

Lumix G7 M 4/3 camera

 

 

This is a fantastic image beginner or not

[Elp]

Have you managed to use the script before? I don't use bias as I'm using an astro camera and subtract the dark flat master from each flat prior to creating the master flat. Then when calibrating the images I only use the master dark and master flat.

The RGB equalisation is what also stuck out for me but you say it doesn't make a difference. If you check both images side by side and get each histogram looking the same do they still look significantly different? Things like photometric colour correction simply carry out curves adjustments and balance the peaks of r, g and b which you can also do manually afterward.

[Cassiopeia1]

52 minutes ago, Elp said:

Have you managed to use the script before? I don't use bias as I'm using an astro camera and subtract the dark flat master from each flat prior to creating the master flat. Then when calibrating the images I only use the master dark and master flat.

The RGB equalisation is what also stuck out for me but you say it doesn't make a difference. If you check both images side by side and get each histogram looking the same do they still look significantly different? Things like photometric colour correction simply carry out curves adjustments and balance the peaks of r, g and b which you can also do manually afterward.

Yes I can use the scripts, mostly the OSC-preprocessing script. That is what produced the 2nd image above and how I arrived at the final processed image eventually(via photoshop).

RGB eq and Cosmetic correction made a small difference to the extreme green hue but that is not really the problem.  Siril can easily get rid of the green hue. The main issue is there is virtually no detail in the object(the spiral arms in this case). It's like a single sub, rather than a stack of 160 subs.

[Swillis]

46 minutes ago, Cassiopeia1 said:

It's like a single sub, rather than a stack of 160 subs.

Have you checked all the intermediate files are created in the directories you expect them to be in?

 

I have not used Sirilic, but do you get a console view like in Sirilic where you can see what has happened in the background? That may help work out where the error is.

[WolfieGlos]

I've never used Sirilic, but you can stack multiple sessions in Siril.

It was explained to me in the link below by @ONIKKINEN - although we were talking about different scopes and image scales, it covers the multiple session scenario as well.

I still follow this routine to this day, and I've managed to automate it a little, in that after I have imported all of the "pp_" light files and added them to their own sequence, I have created my own script that automatically registers and stacks them. I'll just review the graph and cull the worst ones beforehand.

Although what is described in the thread is stacking manually (which is better), if you aren't comfortable with that yet, you can still use the OSC_Preprocessing script to generate your files on a PER NIGHT basis, delete all of the files in the "process" folder EXCEPT for the pp_light.fits files, and then follow the same routine to add them to a new sequence.

Hope that helps.

 

[Cassiopeia1]

9 hours ago, Swillis said:

Have you checked all the intermediate files are created in the directories you expect them to be in?

 

I have not used Sirilic, but do you get a console view like in Sirilic where you can see what has happened in the background? That may help work out where the error is.

Hey Swillis,

yes I believe so. Sirilic creates an analogous process folder to Siril and all the pp_lights are there. Each has the same appearance as the stacked image essentially

[Cassiopeia1]

8 hours ago, WolfieGlos said:

I've never used Sirilic, but you can stack multiple sessions in Siril.

It was explained to me in the link below by @ONIKKINEN - although we were talking about different scopes and image scales, it covers the multiple session scenario as well.

I still follow this routine to this day, and I've managed to automate it a little, in that after I have imported all of the "pp_" light files and added them to their own sequence, I have created my own script that automatically registers and stacks them. I'll just review the graph and cull the worst ones beforehand.

Although what is described in the thread is stacking manually (which is better), if you aren't comfortable with that yet, you can still use the OSC_Preprocessing script to generate your files on a PER NIGHT basis, delete all of the files in the "process" folder EXCEPT for the pp_light.fits files, and then follow the same routine to add them to a new sequence.

Hope that helps.

 

That's fab thank you. I will be adopting this workflow going forward I think. Rich from Deep Space Astro has a good video on manual stacking which I have practiced a bit. The method of running the script and then only retaining the pp_lights seems like a nice easy way to do a few multi session images so I can concentrate on my rig and alignment side of things and a little less on trying to figure out this current problem. Many thanks again!

[Swillis]

9 hours ago, Cassiopeia1 said:

Sirilic creates an analogous process folder to Siril and all the pp_lights are there. Each has the same appearance as the stacked image essentially

Can you take the r_pp_lights from Sirilic and stack them manually in Sirilic and see what you get?

Maybe there is an error in the Sirilic script which means they don't get stacked or only one gets stacked.

Edited September 3 by Swillis
correction

[Swillis]

Also, have you checked the Sirilic log to see if has any errors? We're all the images registered properly?

[Cassiopeia1]

On 03/09/2024 at 16:48, Swillis said:

Can you take the r_pp_lights from Sirilic and stack them manually in Sirilic and see what you get?

Maybe there is an error in the Sirilic script which means they don't get stacked or only one gets stacked.

Thanks for the advice and really sorry for the delay. Been so busy  and haven't had a chance to log on. 

I intend to go that route alright. I think I will just stick with Siril and manually stack the registered pp_lights from now on