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My first astrophotography project has been to take a decent image of the wonderful M31. Due to the lack of darkness here in Sweden during the summer, my first couple of attempts did not produce any image worth posting here. When astronomical darkness first hit, I did keep on trying to image M31 with better results. I have to say that the stacked and processed image didn't live up to my expectations nor were they anywhere near the potential of my equipment. The first processed image was this one: http://i46.tinypic.com/2luvv9w.jpg (only lights, unsure of how many minutes worth)

(I'm not sure how to post a smaller version of the image, so I'll just supply you with the link).

I'm not one to give up, so I kept going out to image M31 every time the weather permitted and on the second session after taking the previous image (the first session after the previous image caused me a some problems with the equipment, which made me learn a few valuable tips) I managed to get things going. I knew that my previous attempts would've been better if I took darks and flats, so that is what I did this time and it made processing the image a lot simpler and made the stacked file actually look like some of the stacked files I've seen that others have taken.

The results (after around ten minutes worth of processing):

http://i49.tinypic.com/4t6gjt.jpg

16x300s lights

8x300s darks

21 flats

And another attempt at processing:

http://i47.tinypic.com/vhc8d5.jpg

I added some of the exposures that had satellite trails in them as well as one with double the "normal" exposure time and one with less than half of the "normal" exposure time.

Now, I'm actually very happy with the results, considering the image taken two sessions before, but I want to do better. I have a couple of questions that I would like some help with. Firstly, is the second image overprocessed? How good was my focus when taking these images (not yet purchased a bahtinov mask)?

I would also like to know how much better the final processed image could be if it was processed correctly (or by someone with experience). Here is a link to the original stacked file: http://www.2shared.com/photo/EbUW-Gip/Andromeda.html

From viewing the images above, what general advice could you give that might help me take better pictures in the future? I'm planning on putting in some real effort by collecting over ten hours of data on M31 when I've become a better photographer, but as you can see, I'm unable to fit the entire galaxy into view due to the FoV being too narrow with my gear (signature). Would it be possible to take two separate images (one of each half of the galaxy) and then stiching them together? How would I go about doing this without wasting valuable time (considering diffraction spikes and so on)?

I would appreciate any possible feedback!

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Those are great shots! You have over processed both the first and the second set of data. The first being just a bit over and the second much over. Your focus looks pretty good but its a little hard to tell because you have some pretty obvious coma at the corners. You will need to buy a coma corrector to fix this. You could also make a B-mask if you dont feel like buying one. I would suggested taking shorter exposures for the core. Time it so that the core is actually similar to the very first picture you linked. You will need to stack it separately then layer mask them together otherwise you will constantly have a blown out core of the galaxy. There are a couple sticky thread under processing that can help you with that. If you wanted to fit the entirety of the galaxy you will have to do multiple frames like you suggested. You could manual stitch them together or theres programs that can help with that to. I unfortunately dont know more than that on that subject. I was going to suggest more lights to help with the noise but if your planning on 10hrs worth of light then that comment become obsolete now lol. But definitely take more darks than what you have. Even for what data you have now. The exact number or ratio is up for debate as to who you talk to but for me I find that half is my minimum. Sometimes thats good enough--depends on the weather. Colder weather = less noise in my DSLR so I dont need to take as many but during the summer thats a different story. But I would still suggest more darks and a bit more flats to your already existing data. Over all its still a very well done capture of M31!

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Those are great shots! You have over processed both the first and the second set of data. The first being just a bit over and the second much over. Your focus looks pretty good but its a little hard to tell because you have some pretty obvious coma at the corners. You will need to buy a coma corrector to fix this. You could also make a B-mask if you dont feel like buying one. I would suggested taking shorter exposures for the core. Time it so that the core is actually similar to the very first picture you linked. You will need to stack it separately then layer mask them together otherwise you will constantly have a blown out core of the galaxy. There are a couple sticky thread under processing that can help you with that. If you wanted to fit the entirety of the galaxy you will have to do multiple frames like you suggested. You could manual stitch them together or theres programs that can help with that to. I unfortunately dont know more than that on that subject. I was going to suggest more lights to help with the noise but if your planning on 10hrs worth of light then that comment become obsolete now lol. But definitely take more darks than what you have. Even for what data you have now. The exact number or ratio is up for debate as to who you talk to but for me I find that half is my minimum. Sometimes thats good enough--depends on the weather. Colder weather = less noise in my DSLR so I dont need to take as many but during the summer thats a different story. But I would still suggest more darks and a bit more flats to your already existing data. Over all its still a very well done capture of M31!

Thanks! Yes, I am planing on aquiring a Baader MPCC along with the mask and I did try to use the first image in my original post to lessen the overexposure of the core, but either the image is too processed to actually make it better or my processing skills are insufficient (at the moment).

I wanted to take more darks, but due to time constraints at the time, I didn't have time to take more than 8. I'll be aiming for an equal amount of darks and lights in the future.

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Thanks! Yes, I am planing on aquiring a Baader MPCC along with the mask and I did try to use the first image in my original post to lessen the overexposure of the core, but either the image is too processed to actually make it better or my processing skills are insufficient (at the moment).

I wanted to take more darks, but due to time constraints at the time, I didn't have time to take more than 8. I'll be aiming for an equal amount of darks and lights in the future.

You dont need equal amounts of darks to light. It wont hurt you if you do and if you have the time and patients then go for it. I usually go anywhere from 1/2 to 3/4 ratio for me depending on the wheater obviously. Layer masking is tricky. There are several sticky threads on here that point to some great videos. Or can google astro layer masking. Most videos use M42 as their example but its the exact same process you would use for M31.

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