Photographing a COMET (Pt. 2) - Siril and GIMP

[@Brik2246]

thanks for always showing free alternatives

[@HELLO-he3ew]

Thank you for your teaching. I have watched all your videos and managed to capture a comet in a Taiwan city with level 8 light pollution. I'm really touched. Thank you so much!

[@benzomobile]

My best compliments, Nico! I think your video tutorial on Siril / Starnet++ / GIMP comet processing is the best one in the net! Thank you very much!

[@opticat2410]

best tutorial for comet editing. tnx Nico

[@jimporter6084]

Thanks Nico. My comet image came out so-so. The hardest part was removing those star trails which a pretty manual process. I did not have enough data to give me much but it was a wonderful experience.

[@ShevillMathers]

I wish that many media sources took the time to find out the real work that goes into the great green comet images we see them raving about, that the wonderful images are a, not visible naked eye, and b, a lot more than a quick snapshot from the average suburban night sky. Greetings from Tasmania Australia 👍😁🇦🇺🦘

[@PsychMike]

My first time ever shooting a comet and learning how to process a new object has been a doozy and a half -- but this tutorial was super helpful. Thanks for taking time to make this, Nico!!!

[@christopherpsaros766]

Same here, I hope I can finally get it!

[@javierlinaje2339]

Thank you very much Nico for help me to process my first comet and for all I am learning with your videos

[@rcinful]

This is awesome timing! Processing mine right now and this is exactly what I was looking for. Uploaded 2 minutes ago. Lol!

[@menglandau]

That’s a fantastic tutorial

[@jroemling]

Thank you SO MUCH for this, I would have never been able to get this done without your tutorial! I wouldn't have even thought about the fact that the comet moves very quickly relative to the stars. I managed to get a decent enough image today, after my attempt two days ago failed because of all kinds of technical gremlins that resultet in mostly blurry images (I'm still a noob and I am still learning what matters and what doesn't). I had to use a different reference image than the one the software suggested and I sometimes had to open my own reference image again, and I also sometimes had to chose the right sequence again that somehow was already pre-selected in your example. But in the end you taught me a bunch of what all those different tabs and functions in Siril mean and from that I could deduct the necessary steps. Thanks again!

[@雨宮雄平]

This is really what we needed. F2P (free to processing) is always welcome.

[@gregerianne3880]

Wow, Nico! Between your other video using DSS/Photoshop and this one, you've put an incredible amount of work into showing us how to process these comet images. Thank you so much for all that effort! It was all very helpful and much appreciated.

[@benoootjes]

Well, this answers my question on your part 1 video! Thank you for the nice video again! :)

[@sbklb1]

Excellent video. I did not know Siril had comet and asteroid modes. I was able to accomplish my processing in Siril for Mono LRGB with an extension of your method. FYI, the nightly-build versions (1.1.1, etc) have starnet built in. Further, you can use GHS with star combine on the comet and stars by themselves by selecting the image in the star combine UI, getting most of what you did all in Siril.

[@Nishta00]

Thank you for always pleasing us and making us learn so much from you, a hug!

[@Astro.Q]

Thanks for showing some other options. Another fantastic tutorial, Nico. I'll be having a gon in the morning to get my data processed

[@blyster62]

A

[@mistaskate8715]

You are amazing! The amount of great tips and instructions you give to us beginners is incredible!

[@stefanschneider3681]

Thx! I got stuck in the „comet“-mode because I didn‘t understand what it wanted from me 🙈. I thus took one-star-registering with „follow star“ checked and it came out quite well, although the stars were making circles around the comet 🤣 … I‘ll try tomorrow. And I know many of you envie me even having data! First evening of our skiing-vacation up in the mountains was clear so I gave it a shot, I‘m so glad I didn‘t give up!

[@richardforee1342]

Aloha Nico! Great tutorial and final image!

[@prnzssLuna]

Thanks for showing off some Linux stuff too (probably not your goal, but as a Linux user, it's very helpful)!

[@matej.mlakar]

Thanks, Nico. Without this tutorial, I would probably have only files of the comet on my disc without a final image.

[@KarlKyhl]

Thank you, Nico. One thing that I learned (the hard way) is that capturing consistently is important. I reframed several times during capture. When it came time to register and stack on the comet, SIRIL made a mess. I had to go through all captures and group by consistent frames.

[@NebulaPhotos]

Ah, yes, thanks Karl. I should have mentioned that! There was a gap in my captures due to clouds, but the mount continued tracking during that time, and I didn't reframe so the comet registration still worked. After grouping did you stack the stacks?

[@KarlKyhl]

@@NebulaPhotos I believe other stacking programs stack on the actual comet, but SIRIL uses the trajectory. So multi-night captures are out. Also, I think you can use NINA plugins and PHD2 comet guiding to keep a comet somewhat framed. SIRIL’s not gonna like that.

[@NebulaPhotos]

@@KarlKyhl I wonder if 'one star registration' would work in that case. Haven't tried it, but someone in the comments mentioned it worked for them

[@thomashuetten1976]

Very good explanation! Thanks

[@JLCubing]

im following this tutorial 100%

[@IonutNedelcu]

Thanks for the guide! I've been looking for a SiriL workflow for a few days now because DSS did not work with my newest batch of images of the comet.

[@maboleth]

Nico, thanks on your tutorial and wonderful catch of the C/2022! I used a DSLR and Samyang 135mm f2. I managed to catch it between the clouds, had like 30mins to work in total. That being said, I experimented with Siril a bit and the bottleneck is the HDD. Don't use Siril with files on a HDD. Unlike DeepSkyStacker that uses local SSD, Siril puts all files and computations where original files are located - a HDD in this case. This clogs the entire system to unbearable pace.

[@johnknight7293]

Thanks, nice tutorial

[@HattoriHanzo031]

Thanks for the tutorial! I tried to follow the steps, but I got stuck at color calibration part. When I try to do color calibration on one pp_light frame it fails with error "90 stars excluded from the calculation; No valid stars found.". If I first stack the image (registering on the stars), and try color calibration with same parameters it works just fine, but of course the comet is blurred. What can I try so I can calibrate on single frame, or can I somehow copy the calibration from stacked photo?

[@astroindianx]

Thx man, very helpful 👌

[@neslin99]

Thanks a lot for this. It helped a lot!

[@PiXaRPXR]

To everyone watching: If you check task manager while siril is running some scripts you'll notice that the disk that contains your siril home folder is at 100% utilization. If you have both an SSD and a HDD do yourself a favor and use the ssd. The process is going to be tens of times faster because the read speed of an HDD is usually capped at 35MB/s while ssd can be read at hundreds of MB/s

[@christopherpsaros766]

Hello Nico, wonderful video, it has helped me a ton so far, but I got stuck on the color calibration, how can I find the right ascension and the declination of the image? This is my first time photographing a comet so I am a bit stumped. Thanks

[@NebulaPhotos]

Hi Christopher, You can visit here: theskylive.com/planetarium?obj=c2022e3 and put in the location and date/time you captured the comet and it should tell you the RA and Dec of the comet at that time.

[@christopherpsaros766]

@@NebulaPhotos Thank you for that, now how would I format the two when I put them into Siril?

[@NebulaPhotos]

@@christopherpsaros766 The three boxes for each Right ascension and Declination are hours (h) minutes (m) and seconds (s) so just copy paste the appropriate numbers from theskylive into Siril leaving off the h, m, s letters

[@christopherpsaros766]

@@NebulaPhotos Ok, I can give that a try, thank you so much for the help, I am a little new to this hobby and trying to find my way! (Your videos really help)

[@pankajbhambhani2268]

Hi, thanks for this video. I used itelescope to get my images. iTelescope gives me the calibrated images directly, no darks, biases etc. I still want to use Siril for stacking. Can you help with that? Thank you

[@solaryellow123]

DSS didn't do very well on my images. That was the trade off for using something simple versus Siril being a little more complex.. I use Siril for all my deepsky stacks, and never considered it for Comet processing, until this video. Thank you for making it look easy.

[@giuseppececere9815]

By far better than the one done with DSS.

[@mistaskate8715]

If you are having issues in siril, here ate two things that happened to me, and how i fixed it. 1. After color calibration of the chosen pp_light frame clicking save or even save as didn't overwrite the frame in the process folder. Just save the color calibrated pp_light somewhere else, then remove the original file from the process folder and lastly move the color calibrated file to the process folder. 2. After registering siril chose another file than my color calibrated file so I had to go back and choose it again manually, but this time from the r_pp_light sequence. The you are ready for stacking. Just to add - the written instructions are quite simple to understand (at least after watching this video) and helps you understand what you are doing in this tutorial.

[@Taj12354]

I wish I could take a photo of this in Australia, really wanted to

[@lachlanm6279]

You should be able to see it later in the month.

[@kevinashley478]

Hey Nico. A bit off topic, but I am looking for a power bank that I can use to power my T3i via the dummy battery and my dew shield. Would you have a recommendation? Or could you tell me how to figure out how much power I need for both? Thanks in advance.

[@RobertKarlBerta]

I use Photo Shop's Dust and Scratches to remove stars or reduce them to what ever I want. You can than add them back in later from another shot of the stars.

[@nhaven5555]

Have you reviewed the sigma fp-l yet? Thanks.

[@maboleth]

A nice way to remove the trailing stars from the Comet image is to use Dust & Scratches in Photoshop. I know that isn't GIMP, but this gets the job done nicely and uniformly. Just make a mask for the comet and experiment with the Dust & Scratches parameters after you get rid of the gradients. For me that was Radius 130, Threshold 17. Maybe Wavelet Denoise filter would do something similar in GIMP, as a substitute.

[@clipwat1511]

can't get starnet running on macos (monterey). I followed your instruction and runned the commands. There was always this reply "no such file or directory". any suggestions?

[@NebulaPhotos]

You first have to be in the directory with those files. So before running the commands type in ‘cd’ space and drag in the Starnet folder into terminal (I show this in the video), press enter. You will now be in the Starnet folder in the terminal and the commands should work

[@clipwat1511]

i did. but now I see, that the commands have been changed. now it worked.

[@NebulaPhotos]

Yes, sorry! my mistake. I copy pasted the commands that worked with Starnet v1. Glad you got it working

[@talktime_s]

Is it possible if we could get the images of the comet or is it patreon only?

[@bobbypungov1877]

How do you get the metadata in color callibration??? This never works for me! :(

[@BasketxCase]

Is the image in the credits flipped or the one during edit? I've confused wondering if mine was flipped because when I upload them to astrometry to find a reference star it flips my comet images and I don't understand why.

[@NebulaPhotos]

It is probably flipping them so that 'north is up'. If we could actually see the ion tail in the sky it would be pointed up from our vantage point. Personally, I just rotate to whatever angle I think looks good.

[@WaddyCo]

Siril is not working for me. Im using a mac, you got any suggestions?

[@NebulaPhotos]

In what way is it not working? Other than Siril, the other major option for Mac is Pixinsight ($) and there are many tutorials on it.

[@duartefaria7134]

I can see you have a new mic.

[@Kevin.kistermann]

Sorry doesn`t work for my files, after color calibration i only have white images. But i shot the my last comet image only with 70mm

[@NebulaPhotos]

Hmmm, haven’t seen that. If you just open a single raw file in Siril, what does it look like?

[@Kevin.kistermann]

@@NebulaPhotos the Raw file looks normal, you can Stack them also with calibration frames. I will try the other color calibration.

[@toneywilson2350]

I get smarter every time I watch. 1 of your videos and still dom.t know any thing. Have you though doing a video on . .Lightning Sprites Thanks again

[@fireislandmavic5939]

dude i could not find this comet,

[@mrmonkey6749]

Will i get a hello for being first?

[@NebulaPhotos]

hello

[@profitsdaily9]

"Success is walking from failure to failure with no loss of enthusiasm." -Winston Churchill

[@madkingofnod]

I am Number 99 and I like space and tacos