Stacking Comet Images with Siril Step by Step 

Nicely done! I tried all the pixel rejection methods for the comet stack. Maybe it's just my data but MAD rejection gave me the best result.

Cannot believe I finally just processed my Comet images from Feb 10, thank you very very much from Sydney Australia.

You speak quickly for a French speaker but if we stick with it we learn a lot of things. Thank you so much !

I can't thank you enough. You're the best on the internet explaining siril thoroughly. God bless you man !

Dude you are the best! I really enjoy your tutorials. Please do not stop making them! My comet picture turned out fantastic!

Great tutorial, thanks to you I've processed my photos of Nishimura comet :D

Thank you for this great tutorial. Yeah, it is daunting but I'm gonna give it a try!!

Very good ,easy to follow video. Thanks for showing me how to process comets in siril. Keep up the good work.

Thank you so much mate. Much appreciate.

Thanks Rich. You're the best!

OMG this is good stuff ! I’ve got to start putting all these items in a doc or pdf . All I need now is for you to do a review of the new StellarMate and I’ll be set for the foreseeable future . LOL . Cheers and thanks again .

Thank you for this! Used GIMP at the end instead of Photoshop, but was able to easily figure it out. I watched another large channel Siril comet tutorial and he was definitely missing steps.

I have the same setup! But I'm using a Ioptron Pro mount. I'm new at this and I havent had the chance to go out yet due to the weather and I'm still waiting on my RedCat 51. I went a little overboard. I should of bought a astro camera but instead I bought a used T7i Rebel lens combo. Thought I could use that to learn how to use a Canon camera also. If i'm gonna do astrophotography, then I need to learn photography also right. I bought a Samyang 135mm for the camera. Well now that we all know that I know how to spend money, I'm hoping videos like this will help me use these bad boys. I've always been into space and now I'm at a part in my life where I can take pictures of the heavens. Good informative video! P.S If you don't hear back from me soon, then my wife found out all the money I spent.

Wonderfull job 👍

Thank you for this tutorial. I’ve been using Siril for a long time and I’ve come across something new I was wondering if you could help me with. When I do the background extraction, when it comes time to be more specific and deselect some red squares where the comet tail may be, as soon as I right click on a square Siril just closes. I’ve never had this happen before. What is going on here? I can’t find any other way to deselect any red squares.

Great photo, i have a lot to learn👍

First I want to thank you Rich so much for doing this video that any beginner like me can follow without any problem. Siril is a great program and I have used it a lot in my own workflow together with DSS, I like both results and I combined always both for get the final image (I know is a double work...). With comets, when we have a project with this special sky target is always been a headache the star trail left in the comet only stacking and for the first time you are proposing a fair and magnifique way to deal with it. I follow step by step your workflow and I have some questions: Background Extraction 1) When is generate the grid in the first frame of the sequence, that grid is moving accordingly to the position of the comet in the next frame? Because if the comet is moving 'fast', more than the half of the sequence will get a grid point over not only in the head of the comet but also in the tail, and that maybe will affect some information of the comet?. Maybe, the area where the comet will move could be left free of grid points that more or less I know the comet will be moving. But If this is right, there is a problem if I'm not doing the Background extraction in that moment and do it later when I have the final starless stack? 2) Is a problem if I do not want to do a Photometric Color Calibration in my comet frames? 3) Why is been doing an export of files mtf_bkg_pp_light and not just get those files directly to the python script? Is around two days (since I discovered your video) I'm testing this workflow for several reason: ** in the stack starless comet, the head of the comet present a 'line' and is not pinpoint as should be. In fact also the tail is more thick than should be. Which meant sadly I'm not getting a defined structure of the entire comet and several details are getting blurred. ** When I check the comet.seq and _s.fit frames I noticed that several frames are jumping around but 'close' to the comet reference position that became the first frame ?, and is not the reference frame selected previously in the workflow (bkg_pp_light). 10 out of 40 frames are over the comet head of the new reference frame. Other 11 frames match same position out of the reference frame, other 7 out of the reference frame, and the rest 'close' around. I did the same box position in the first frame and look each frame of those sequences. I would show you my results of this situation compared for example the stack comet result with the same frames done in DSS. DSS ask mark the comet position in 3 frames, the first, one of the middle also as reference frame and the last. Not sure that this allow that program get better pinpoint result in the comet final stack. Other thing to get into account is that the data of the comet I have, the comet was moving fast so each frame of the sequence there is a noted displacement of the comet, but this was not a problem in the stack comet only result of DSS. In the tests I have done I could not improve the stack in the starless comet, doing the box more little, around the head comet, changing method, etc I always note that the frames jumps around of the reference frame. Also I do not understand why in the exported and converted starless frames, the reference frame is changed and if this is maybe part of the problem. I guess that this kind of problem isn't noted also if the data is taken with scopes focal lenght under 400mm. Our data come from a session done 29/1 with a Newton 200-800mm 30sec exposition ISO 2000 Canon Ra. I will continue to test this workflow and if you have any suggestion I will appreciate. Many thanks again for this effort and the very informative and formative videos you are doing and for your attention CS, NC

Before I get too far in the video - I only have lights and darks. Can I still use this process as long as I create the relevant folders? (16GB M1 MacBook Air. I don’t have Photoshop and I’ve never used GIMP.) Thank you.

The skymap coordinates on my end siril says unable to plate solve despite the coordinates correctly

Hi!I have imaged the comet using Explore Scientific 127mm achromat and NIKON D5300. When I get to the point where I have to fill the focal lenght and pixel/chip size i dosn't let me continue. An error about these specs comes out. :/

FWIW I watched 18 minutes of this before you mentioned Photoshop, which I don’t have. Is there a free alternative to PS that would cope with those steps? 🇬🇧

Thank you for the tutorials. They've been really helpful. For some reason, whenever I try plate solving my photo always becomes super lime green and I'm not sure why. I'm wondering if I have too much magnification (my setup consists of an 8" SCT w/ a f.6 reducer and a planetary camera). Going to keep messing around w/ different settings and seeing if I can get something to work.

Nice video. & Thanks. You have good star data without trailing. Is there not a way to copy/ paste just the comet into the star image so there is no trailing? Maybe by free hand selecting comet with feather mode on and copy paste? Ill try this once finished with siril processing (it's taking forever! ).

The only software that worked for my long exposures comet stack was ASTAP. I was guiding on comet but the guiding got affected by passing stars, so I ended up with the comet in four different positions. I selected the object to be center of the comet for each photo and the end result was bot bad😊