Multiple Nights Stacking - SIRIL

[cwine]

Hi all,

I've seen threads on stacking multiple nights data before, but all refer to DSS, which isn't useful for me on a Mac, as I have to use Siril.

I'm wondering how I might go about stacking multiple nights data. If I take different darks, flats, and presumably keep the same bias frames, then how would I go about stacking them. Siril is much more hands on than DSS and doesn't automate the process, so I need to know exactly what to do. 

Thanks in advance for any help!

[alacant]

40 minutes ago, cwine said:

I have to use Siril

Hi. A distinct advantage then;)

What version of Siril do you have, what camera is it and was it removed between sessions?

Cheers

[cwine]

34 minutes ago, alacant said:

Hi. A distinct advantage then;)

What version of Siril do you have, what camera is it and was it removed between sessions?

Cheers

Hi - it looks like I have version 0.9. I have an unmodified Canon 600D. I havent actually done multiple sessions yet, but I am planning to do it on different nights, removing the camera and setup, and then setting up on a different night. Any ideas what to do?

[prusling]

Sirilic (the simplified front-end utility for Siril) supports multi session. 

[alacant]

 

Update to the latest version: 0.99.3. On Mac you'll need to build it from source. 

Don't take dark frames but instead dither between each light frame.

One off: Take bias frames and stack to make a master bias.

For each session:

Take flat frames.

Pre process each flat with the master bias. Stack the pre processed flat frames to form a master flat.

Pre process the light frames with the master bias and the master flat. Don't forget to check 'debayer before saving'

One off:

Put the all the pre processed light frames in the same folder and open as a sequence. Register and stack using one of the clipping algorithms.

That's it.

HTH.

Edited August 1, 2020 by alacant

[alacant]

1 hour ago, cwine said:

removing the camera

That's a pity.

[cwine]

1 hour ago, prusling said:

Sirilic (the simplified front-end utility for Siril) supports multi session. 

Ive tried installing Sirilic, and seem to have a folder full of Python files. I'm not sure how to open it up and actually run it to get that front end though. Any ideas? Sorry if I'm being ignorant, but I just started with this!

[cwine]

34 minutes ago, alacant said:

 

Update to the latest version: 0.99.3. On Mac you'll need to build it from source. 

Don't take dark frames but instead dither between each light frame.

One off: Take bias frames and stack to make a master bias.

For each session:

Take flat frames.

Pre process each flat with the master bias. Stack the pre processed flat frames to form a master flat.

Pre process the light frames with the master bias and the master flat. Don't forget to check 'debayer before saving'

One off:

Put the all the pre processed light frames in the same folder and open as a sequence. Register and stack using one of the clipping algorithms.

That's it.

HTH.

Oh ok, so what you're essentially saying is fully preprocess master light frames for each night and then register and stack them together? I can't dither as I am tracking with a Star Adventurer, unguided, so will have to do it with darks (if that's not a problem). I'm not sure if I've figured out how to open up frames as a sequence, but I'm sure by playing around with it a little bit I'll figure it out!

Thanks a lot for the help - much appreciated! Hopefully can get some good Andromeda pics with this technique (I got my first tracked photograph ever a couple of nights ago!)

Ive tried to download the latest Siril software from the website, and have clicked 'check for updates' within Siril, and it says I'm up to date - I'm not sure what you mean by 'build it from source' though? Could you explain further?

Edited August 1, 2020 by cwine

[prusling]

16 minutes ago, cwine said:

Ive tried installing Sirilic, and seem to have a folder full of Python files. I'm not sure how to open it up and actually run it to get that front end though. Any ideas? Sorry if I'm being ignorant, but I just started with this!

Hi, sorry I use the Windows version. The following page (in French) https://astroslacholet.wordpress.com/2020/04/11/utilitaire-conv2siril/ advises the following which may apply to MacOS:

Under linux, you must make the "sirilic.pyw" file executable or launch online command in a terminal: python3 sirilic.pyw
You can associate the extension ".pyw" with the python program (/usr/bin/python) in your browser.

This may be a bit of a pain to set up but I believe it is worth it as the resulting front-end is very easy to use. I have written a (Windows) tutorial which is referenced on the link above.

[bottletopburly]

1 minute ago, prusling said:

Hi, sorry I use the Windows version. The following page (in French) https://astroslacholet.wordpress.com/2020/04/11/utilitaire-conv2siril/ advises the following which may apply to MacOS:

Under linux, you must make the "sirilic.pyw" file executable or launch online command in a terminal: python3 sirilic.pyw
You can associate the extension ".pyw" with the python program (/usr/bin/python) in your browser.

This may be a bit of a pain to set up but I believe it is worth it as the resulting front-end is very easy to use. I have written a (Windows) tutorial which is referenced on the link above.

 Beat me to it Just about to link your tutorial http://download.startools.org/Siril with Sirilic.pdf

[cwine]

2 minutes ago, prusling said:

Hi, sorry I use the Windows version. The following page (in French) https://astroslacholet.wordpress.com/2020/04/11/utilitaire-conv2siril/ advises the following which may apply to MacOS:

Under linux, you must make the "sirilic.pyw" file executable or launch online command in a terminal: python3 sirilic.pyw
You can associate the extension ".pyw" with the python program (/usr/bin/python) in your browser.

This may be a bit of a pain to set up but I believe it is worth it as the resulting front-end is very easy to use. I have written a (Windows) tutorial which is referenced on the link above.

Ah great thanks for your help - I'll see what I can do!

 

[alacant]

1 hour ago, cwine said:

how to open up frames as a sequence,

Simply change to your working folder. The one with the files you wish to process.

Now hit the sequence tab > search for sequences

HTH

[alacant]

1 hour ago, cwine said:

you're essentially saying is fully preprocess master light frames for each night and then register and stack them together

If you remove the camera, yes.

 

1 hour ago, cwine said:

build it from source

Ask here. 

You may find it easier on a Linux or Windows machine. 

Cheers

[alacant]

2 hours ago, cwine said:

I can't dither as I am tracking with a Star Adventurer,

Is it faulty?

 

[cwine]

2 hours ago, alacant said:

Is it faulty?

 

I didn't think dithering was an option unless you were guiding or using software while tracking? I am just using the Adventurer on its 'celestial' setting, which follows the rotation of the sky without any other special options like dithering etc. Maybe I'm wrong but I haven't seen any setting for dithering!

[alacant]

Hi

Ah, ok. So connect a camera app. I think that using dark frames is going to introduce more noise but YMMV.

Cheers.

[cwine]

5 hours ago, prusling said:

Hi, sorry I use the Windows version. The following page (in French) https://astroslacholet.wordpress.com/2020/04/11/utilitaire-conv2siril/ advises the following which may apply to MacOS:

Under linux, you must make the "sirilic.pyw" file executable or launch online command in a terminal: python3 sirilic.pyw
You can associate the extension ".pyw" with the python program (/usr/bin/python) in your browser.

This may be a bit of a pain to set up but I believe it is worth it as the resulting front-end is very easy to use. I have written a (Windows) tutorial which is referenced on the link above.

Haven't been able to get it to work on Mac - been trying to run it but its all been getting very confusing and the modules it is calling on won't run. I might have to leave Sirilic unfortunately

[cwine]

16 minutes ago, alacant said:

Hi

Ah, ok. So connect a camera app. I think that using dark frames is going to introduce more noise but YMMV.

Cheers.

Good idea - thanks so much for your help!

 

[alacant]

14 hours ago, cwine said:

I might have to leave Sirilic

If you can get the latest version of siril, with its sumptuous new user interface, you'll find it much easier

Or maybe even easier, get a linux or windows box for your astro imaging?

Cheers

Edited August 2, 2020 by alacant

[ollypenrice]

Do yourself a simple favour and orientate your camera along RA and Dec each night. Get the camera parallel with the C/W bar or dovetail by eye and then do a 10 second sub while slewing slowly in one axis. The resulting trails show the current camera angle. Get the trails horizontal or vertical. This will save you much unhappiness!

Olly

[michael.h.f.wilkinson]

I have done a couple of multi-session images, all readily supported by recent editions of Astr Pixel Processor (also available for Mac, but not free). You simply assign different lights/flats/darks/bias frames to different sessions/filter bands, and it stacks away. Personally, I tend to use a slightly different, short-cut approach of first stacking the data of each session, and letting APP compute a weight map for each pixel. Once I have a set of processed results from each session, I load these into APP with the weight maps and integrate the results. In this way, it is far faster to add a new session to an existing interim result. I do not see any problems in the resulting images that suggest this is somehow the wrong approach. Below is a three-session result (which needs more data, of course)

Maybe Siril supports a similar workflow.

[bottletopburly]

I use Siril scripts then the resulting fit file from each session I just stack these together, seems to work I was told that way by one of the siril team that posts the YouTube videos, quick and easy , maybe the lazy way but it works .

[cwine]

On 01/08/2020 at 15:02, cwine said:

On 01/08/2020 at 14:27, alacant said:

 

 

On 03/08/2020 at 18:53, bottletopburly said:

I use Siril scripts then the resulting fit file from each session I just stack these together, seems to work I was told that way by one of the siril team that posts the YouTube videos, quick and easy , maybe the lazy way but it works .

 

Hi, so ive tried to do this by putting pre processed light frames from two different nights into a single folder, but it seems that to open a sequence, you need the .seq file within the folder from the session. But that .seq file only relates to each individual set of data. There doesn't seem to be a way to simply open up all .fit files within a folder, as it only seems to open up the files that were processed with the particular .seq file you are choosing (there is one of these for each for the two different sets of data).

Ive tried to update Siril but it seems very difficult on a Mac, and I don't have access to a Windows or Linux, and haven't been able to get Sirilic to work. Can you direct me, because I would love to be able to stack these multiple nights data but I'm struggling with this .seq issue!

 

[bottletopburly]

3 hours ago, cwine said:

 

I will have a look see if I can jot down sequence 

[alacant]

7 hours ago, cwine said:

There doesn't seem to be a way to simply open up all .fit files within a folder,

Create an empty folder.

Change the working directory to that folder.

Siril -> Conversion

Hit the '+' button

Select the processed files you want from the first session without the .seq file.

Hit the '+' button

Select the processed files you want from the first session without the .seq file.

Give the sequence a name

hit 'Convert'.

--- --- ---

You now have a sequence loaded with all the frames.

HTH

Edited August 7, 2020 by alacant