Does anyone use Siril?

[StuartT]

I've only just discovered it and trying it out on some data.

If anyone here has experience of it, or knows of any good tutorials, I'm all ears.

Thanks

[Dazzyt66]

Hey Stuart, I use Siril a lot. This is the best tutorial that I've used from the start and get great results:

 

Edited October 11, 2021 by Dazzyt66

[GoldTop57]

I started with this: https://siril.org/tutorials/tuto-scripts/

[AstroMuni]

17 hours ago, GoldTop57 said:

I started with this: https://siril.org/tutorials/tuto-scripts/

+1 I use only SIRIL and Gimp to do any touch up work post processing.

This is a great place to learn the basics. I follow this workflow and this gives great results.

@StuartT also take a look at the Sirilic tool which has a GUI interface for generating and running scripts.

Edited October 12, 2021 by AstroMuni

[StuartT]

I just found this video which is perfect for a noob like me. He also explains a lot of really great Photoshop tricks!

Thoroughly recommend this! I think I now prefer SiriL to Astropixel Processor. For one thing, it's MUCH faster!

 

Edited October 13, 2021 by StuartT

[markse68]

I started with Siril but am still very much a beginner. I tried Startools but it is sooo slow I just can't get on with it- it's way too painful to experiment with and learn. Siril is lightening fast by comparison but I don't think it can do the fancy stuff that others can. The photometric calibration is good though and the background extraction which you can run on a sequence pre-stacking seems to work pretty well. I've never got anything useful from deconvolution though. I'll watch those videos and see if I can learn something from them

Mark

Edited October 13, 2021 by markse68

[ONIKKINEN]

I use siril, i like the simplicity and user interface. I tend to do background extraction, photometric colour calibration (a blessing, works every time) and a stretch with SIRIL and then move on to photoshop for the nonlinear part of processing.

 

The background extraction tool works well for most projects, especially if all the data was taken on the same night.

 

Stretching with asinh transformation first and them the histogram transformation nicely retains colour and i find that sometimes only a minor saturation boost is needed.

 

Recently switched stacking from DSS to siril with sirilic too. Sirilic stacking allows a background exraction per sub in the stacking process, which is proving to be a necessity for me. Only problem with stacking in sirilic is that it takes about 1gb per sub taken for stacking from my harddrive, so a dedicated SSD is needed.

 

Hard to beat for the price of free.

[BCN_Sean]

I've been using it for a bit, and still getting my head around it, well still getting my head around the post capture in general.  One thing I've found with it is that the background extraction tool if run after photometric can pull out all sorts of nasties if the optics used aren't up to snuff.  As for the photometric itself, with shooting an SLR and converting within SiriL, I've found it best to open one of the untreated lights in astap, solve that and then enter the co-ordinates manually (and maybe downsample as well) as sometimes even if the image is out only by a smidge of a degree to what it expected then it may fail to run.

The deconvolution, that is something that I've had hit and miss results with as well; if the image is fairly under sampled, then it doesn't work well but if it's not too far off the mark then it works well.

Best thing I've found with it is to extract the background before registration (very useful if stacking multiple nights) and then running that before any colour calibration on the stacked fit.

The biggest gotcha I've found with the newer version, is that when opening a freshly stacked fit file, it looks though it's been cropped to remove the border but it's best to crop it in a bit further as there may still be some stacking artefact present that it's missed or just masked.

[Dazzyt66]

What I love here is that you learn something every day! I didn’t realise you can do background extraction before stacking so I will give it a try! If I don’t use Startools, my processing workflow in Siril after stacking (and generally works well for me) is:

Background Extraction

Remove Green Noise

Photometric calibration (using get info from image)

Crop (use auto stretch to see where then go back to linear - photo metric cal will often fail if you crop before)

sinh stretch

histo stretch

 

After that I use gimp for final tweaks. 😊

Edited October 14, 2021 by Dazzyt66

[markse68]

On 11/10/2021 at 18:28, Dazzyt66 said:

Hey Stuart, I use Siril a lot. This is the best tutorial that I've used from the start and get great results:

 

I watched this video- he takes a while to get to the point but i did learn a couple of new things so thanks! 

I have a question for the experts though- when he imports the Siril file into Gimp he selects “convert” in the colour profiles opening dialog box. I always selected “keep” Should i be converting? What does it mean/do?

Mark

[BCN_Sean]

7 hours ago, Dazzyt66 said:

I didn’t realise you can do background extraction before stacking so I will give it a try!

Yeah, I generally use it in a script or via the command line (eg seqsubsky light 1), but there is an option in the interface as well, just open the light sequence and apply; a polynomial order of 1 should be sufficient on untreated lights.  Just helps getting rid of simple gradients which when stacked would turn in to a complex one; then after stacking just hit it again.

[markse68]

1 hour ago, BCN_Sean said:

Yeah, I generally use it in a script or via the command line (eg seqsubsky light 1), but there is an option in the interface as well, just open the light sequence and apply; a polynomial order of 1 should be sufficient on untreated lights.  Just helps getting rid of simple gradients which when stacked would turn in to a complex one; then after stacking just hit it again.

remember to tick the "apply to sequence" box though- I usually forget...

Mark

[StuartT]

Thanks everyone. 

The photometric calibration is just wonderful! Works like a dream.

I can't manage to get the asinh transformation to do anything useful tho. This is puzzling. In my hands, it just leaves the image totally dark. Fortunately the automatic gear button in the histogram tool seems to do a nice job so I just use that

[markse68]

44 minutes ago, StuartT said:

Thanks everyone. 

The photometric calibration is just wonderful! Works like a dream.

I can't manage to get the asinh transformation to do anything useful tho. This is puzzling. In my hands, it just leaves the image totally dark. Fortunately the automatic gear button in the histogram tool seems to do a nice job so I just use that

Hi Stuart I learnt from the first video posted above that you can do multiple iterations of the arcsinh stretch- max it out, close it then do it again! I never knew that! And he was doing some arcsinh, then some histo, then some more arcsinh. I learnt a few new things form that video

Edited October 14, 2021 by markse68

[StuartT]

2 hours ago, markse68 said:

Hi Stuart I learnt from the first video posted above that you can do multiple iterations of the arcsinh stretch- max it out, close it then do it again! I never knew that! And he was doing some arcsinh, then some histo, then some more arcsinh. I learnt a few new things form that video

yes, I tried doing it a few times and maxing it out, but nothing happened. I think it very much depends on the type of image you have.

But I am very happy with Siril so far. It made a lovely job of my first ever attempts at DSO imaging and with remarkably little effort or skill from me 🤣

 

[Dazzyt66]

4 hours ago, StuartT said:

Thanks everyone. 

The photometric calibration is just wonderful! Works like a dream.

I can't manage to get the asinh transformation to do anything useful tho. This is puzzling. In my hands, it just leaves the image totally dark. Fortunately the automatic gear button in the histogram tool seems to do a nice job so I just use that

I do love Siril for its ease of use. I usually use asinh just before I use the histo - it usually works by the time I get to 100 - I don't think I've ever gone over 200 with it as it washes stuff out. Whilst I was getting used to Siril I used the histo 'nuke' (auto) button and then just wound it back a bit. With practice you'll quickly get in a flow for quite quick processing with decent results.

[ONIKKINEN]

10 minutes ago, Dazzyt66 said:

it usually works by the time I get to 100 - I don't think I've ever gone over 200 with it as it washes stuff out.

This sounds like the complete opposite of me. I always crank it all the way right, to 1000. Still the image looks mostly black with some of the brighter stars visible. Probably because all of my signal is within the first 200ADUs or so.

[Paul M]

On 13/10/2021 at 18:28, StuartT said:

I just found this video which is perfect for a noob like me.

Thanks for the link. I've watched a few other Siril tutorials, each time thinking I'd finally got the hang of it. Still, so far I've yet to point it at a folder of subs and get an image out the back end!

More than once, every time really, we just sit there looking at each other in a Mexican Standoff. Both waiting for the other to make a useful move!

With my previous main camera, ASI178, I generally took lights and darks, flats not really needed as the frame was well inside the vignette but that camera has gross amp glow. My new main camera, ASI071, has zero amp glow but really is bugged by vignetting so I mostly take lights and flats, no darks needed. Siril just doesn't understand me. Why doesn't it just use the provided subs as identified?

Anyway, perhaps now I will make headway...

[BCN_Sean]

5 hours ago, markse68 said:

remember to tick the "apply to sequence" box though- I usually forget...

Ah, that's not too bad... Forgetting to click "Apply" before clicking on OK after spending a few minutes getting the perfect histogram is one that gets me more often than not!

[Dazzyt66]

10 hours ago, BCN_Sean said:

Ah, that's not too bad... Forgetting to click "Apply" before clicking on OK after spending a few minutes getting the perfect histogram is one that gets me more often than not!

Ain’t we all done that!! 😂

[StuartT]

22 hours ago, ONIKKINEN said:

This sounds like the complete opposite of me. I always crank it all the way right, to 1000. Still the image looks mostly black with some of the brighter stars visible. Probably because all of my signal is within the first 200ADUs or so.

me too! I take it up to the top and still I have a mostly black image.

 

22 hours ago, BCN_Sean said:

Ah, that's not too bad... Forgetting to click "Apply" before clicking on OK after spending a few minutes getting the perfect histogram is one that gets me more often than not!

Except the 'preview' box is ticked by default, so any changes I make in Asinh should be visible even without clicking 'apply'

[BCN_Sean]

2 hours ago, StuartT said:

Except the 'preview' box is ticked by default, so any changes I make in Asinh should be visible even without clicking 'apply'

Not in asinh, the one on the actual histogram; I can't remember how many times I've forgot to hit apply and then just hitting close.  When it comes to the way to commit a modules change in SiriL it looks like there's been at least three different development teams on it, each with their own chain of design and that has introduced a few little flies in the soup because of it and if not wary of it (or it's like my usual, about five in the morning) then it's easy to get bitten with them.

[AstroMuni]

On 13/10/2021 at 19:22, ONIKKINEN said:

Only problem with stacking in sirilic is that it takes about 1gb per sub taken for stacking from my harddrive, so a dedicated SSD is needed.

It should take the same amount of space as when doing via Siril directly. After all it creates a script which then executes in Siril. You can configure it to do processing in 16bit as that would help.

[ONIKKINEN]

1 hour ago, AstroMuni said:

It should take the same amount of space as when doing via Siril directly. After all it creates a script which then executes in Siril. You can configure it to do processing in 16bit as that would help.

It does take the same amount, i have hundreds or thousands of 50mb files per stack. Doing background extraction and cosmetic correction (not sure if necessary) will add another set of subs to be saved when stacking. Of course i can use DSS which is less hungry in terms of space but the results are worse.

I dont think 16bit is enough, i am shooting short exposures and the difference in background and signal can be only 0.1 ADUs in the 32bit stack. This would drown in noise with 16bit, unless i am completely wrong on how it works.

[AstroMuni]

1 hour ago, ONIKKINEN said:

This would drown in noise with 16bit, unless i am completely wrong on how it works.

My reckoning is that if your original image was captured in 16bit then any further processing can be done in 16bit. Its not like we are adding more info at that stage. But I am also not that close to understanding this.