INeedSomeHelp

This is the result. I think more skilled post-processors would have improved the final outcome but I still think it is quite cool!

I thought I was quite a big boy with my 27 minutes ;). As for the processing, this is why I made this post. I felt that there is definitely ways to improve the image post-hoc. Nice images btw.

Yep, I found those tutorials and actually followed this one! However, I use the combination of SiriL and photoshop, as well as a 100mm macro lens. Nice that I can take less calibration shots, it feels kind of bad to burn away your shutter with a lens cap on your lens. Not doing the background correction means a "cleaner image" (i.e. less grain), but then I have an orange tint in the bottom of the image, which fades to deep blue at the top. I will maybe try some nebulae soon, such as the eagle or lagoon nebula!

I have 50 dark frames, 50 flat frames and 75 bias frames. This should be sufficient right? Also, there is no grain before I perform a background correction, it really is the background correction which causes it. I also took about 650 lights at 2.5 seconds each. This should mean (if I did the math correctly) that I have a total integration time of 27 minutes. I don't know if increasing the amount of light frames will improve the image much right?

This is what I can get following your tutorial. How would you improve this image? I still have to do some star reduction.

I haven't read that, I will start with this! Do you think that the graining which occurs after background extraction is caused by excessive light pollution? BTW, do you guys think that the automatic stretching incorporated in SiriL yields good results? Or should I do it manually (I already tried in photoshop, but couldn't get a good image that way, the automated SiriL stretching performed better).

Nice, I will have a look at this!

2 weeks ago I created a post asking how to improve my Andromeda image. Turns out I made a classic beginner mistake and Andromeda was just out of frame. I have, however, repeated this experiment, and have quite some light frames of M31 now! I could use some help with the post processing, I can manage myself but I got such good tips in my last post that I figured I might as well ask for advice once more. Attached to this post are the output of a stack performed in SiriL AND 2 .tif files. I already performed some post processing steps in SiriL, which resulted in the 2 .tif's. In Siril I: 1) Applied the automatic Color Calibration (for M31 ofcourse). 2) Corrected the green noise. 3) Performed background extraction on 1 image (and one image without). The background extraction (as I understand it) is to get rid of the gradient in background color. In my non-background corrected image you can see that the background at the bottom is quite orange (light pollution from a road I think). The background extraction fixes this quite nicely, BUT it also causes some very heavy graining to occur. 4) Lastly I applied the stretching algorithm that is build in in SiriL under "Histogram Transformation" and saved the .tifs as a 16 bit image. 5) Exported both a .tif without and one with background extraction (2 images are attached). I also attached the image that you obtain directly after the stacking (called result.fit). So what happened with the background extraction causing this graining? Should I skip it, or perform it differently? Furthermore: how to proceed with a .tif in photoshop. I think, with good editing and processing, there might be a good image there! Cheers. stretchedwithbackgroundcorrection.tif stretchedwithoutbackgroundcorrection.tif.tif result.fit

I have a new image, much better! I have stacked about 650 light frames in SiriL; I: 1) Applied the automatic Color Calibration (for M31 ofcourse). 2) Corrected the green noise. 3) Exported both a .tif without and one WITH background extraction (2 images are attached). The background extraction (as I understand it) is to get rid of the gradient in background color. In my non-background corrected image you can see that the background at the bottom is quite orange (light pollution from a road I think). The background extraction fixes this quite nicely, BUT it also causes some very heavy graining to occur. Lastly I applied the stretching algorithm that is build in in SiriL under "Histogram Transformation" and saved the .tifs as a 16 bit image. I know you can perform manual stretching in Adobe Photoshop but this was quite difficult and since SiriL can do this job for me, with quite good effect, I show my .tifs in this post. Now I'm curious what to do with that background correction and the graining, and how to proceed in Photoshop! Im already quite happy, you can even see the satellite galaxy. stretchedwithoutbackgroundcorrection.tif.tif stretchedwithbackgroundcorrection.tif

So I now have repeated this "experiment" and I for sure have found M31 now. The stacking will probably take a full night, but soon I will hopefully have something to show.

In that image, I could see Alpheratz quite clearly on the LCD. And that was with a full moon behind me. If I took an image with 1600 ISO some other stars also popped up.

You are correct in that assumption, I am on mac. I think that I will try and follow your "star hopping" directions as they are really detailed and newbie proof. Thanks for that. Before I start blasting again, do you think that at 100mm, f2.8; 1600 ISO and 3s exposure I can clearly see Andromeda after having followed your hopping pattern?

Amazing tips and help! It is very appreciated! In a couple of days I will try again!

Do you mean calibration shots for the test shots? Or already start shooting M31 to try and localize it? And if I am in central Italy, which I am, and Alpheratz is to my east, I should go to the left (north) and up, correct?

Good tip, I think that sitting around 2s. or perhaps 3s. is achievable. Then my new plan: - actually find the M31.... - around ISO 400 - 2-4 second exposures - wide open at f2.8 - frame M31 by taking a 10-15s test shot to see if it is in focus/in my FOV - take 50-80 images and refocus, repeat x amount of times - take the calibration images