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After putting together some kit around two months ago, I thought right here we go get set up the rest should be easy. O’Dear, My first mistake.

focus was my first big issue so whilst I was trying to figure out what the problem was, I decided that I would work on polar alignment. After a few failed attempts I managed to get that done and to be honest I now find that very easy.

 I then ask for help on SGL with regards to the focus issue and after posting some pictures this was resolved. The problem was an extension piece on the end of the field flattener which was stopping me from focusing inward. With that problem solved I tried to take some subs of M51 but as usual the great British weather interrupted me after only 10 x 30 second exposure’s. But I stacked them and messed about with gimp and there in the middle was the faintest image. At least I had got something.

So last week I went out again last week and started imaging The North American Nebula, 

Equipment used, EQM-35 goto mount, Skywatcher 72ED, fully modded canon 450d, no filter used on this occasion. 
I took 56 x 40 second exposures @iso 800.

20 x darks

20 x bias

I did not get any flats.

This was the result any feedback or tips would be greatly appreciated.D5B7E8C9-6818-46CA-B949-6AF57A89FD0E.thumb.jpeg.be873bcb7a74eafa2422a3b9fbd67258.jpeg

There is a dust bunny on there not sure if it is on the camera or telescope.

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You can certainly see the right shape there. You might be better with an easier target like M13 to start with which usually need shorter subs. Also the images definitely improve if you take dark and flat frames.

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+1 for taking flat frames. On the other hand, I wouldn't bother in taking darks with a DSLR. There are several threads in this forum explaining why. Choosing an easier target, like the suggested M13, will make both capturing and processing easier and less frustrating. Good start and congrats!

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Looking at you image there are a few issues, but as a first attempt I would be happy.

A few pointers:

1. I assume you do not have a field flattener from the star shapes - that would help. However, I would not get too hung up on that for now

2. Buy or make a focus mask - it is tricky to get right using the DSLR screen.

3. The dust is almost certainly on the sensor itself. It is too 'clean' to be further away.

4. More total integration time. I would not worry too much about increasing the sub lengths if you are not guiding as you are likely to start getting star trails without perfect PA.

5. Bias, flats and dark flats will be your best option with a DSLR.

To photo M13 you will need very good focus, but good luck. You are on the right track.👍

 

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Jumping from issue to issue sounds very familiar, and getting any kind of result in the end makes it all worth it!

I will echo the above about taking flats, that will allow you to stretch the image harder in processing without the corners going full black.

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Quote

 

Hi

Without filters it is going to be difficult to get great data at this time of the year - it never gets properly dark.

Looks like you have PA sorted, and there is data which shows the general shape of the Nebula. It just looks over-stretched and the black looks clipped. Also, did you correct the colour channels ?

Nico Carver has some useful videos on Youtube which I found really helpful for getting to grips with GIMP. 🙂

 

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1 hour ago, ONIKKINEN said:

Jumping from issue to issue sounds very familiar, and getting any kind of result in the end makes it all worth it!

I will echo the above about taking flats, that will allow you to stretch the image harder in processing without the corners going full black.

Thanks, I will make taking flats a priority during the next session.

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47 minutes ago, Astro Noodles said:

Hi

Without filters it is going to be difficult to get great data at this time of the year - it never gets properly dark.

Looks like you have PA sorted, and there is data which shows the general shape of the Nebula. It just looks over-stretched and the black looks clipped. Also, did you correct the colour channels ?

Nico Carver has some useful videos on Youtube which I found really helpful for getting to grips with GIMP. 🙂

 

I do have alight pollution filter so I will try that next.

I did mess about with the colours, but again it was the first time I have ever used photo editing software.

 I will have a watch of that video later, thanks for the help.

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Posted (edited)

Mmm, it may be worth having a look at a single sub. Even under the difficult conditions these days, the NA nebula is quite forgiving, and 40 min should give a noisy but more detailed image than the one you have posted. I have just bought a modded Canon 700D, and although I tried to test it with the same target, I forgot to charge the battery and had to change my plans last Wednesday. But I took a single photo, 40 seconds, ISO 1600, with a WO Z61 on a Star Adventurer. This is what I got:

IMG_9889.thumb.jpg.7c239be16439c97b3fb86ea0b6415ad2.jpg

Yes, very noisy, as one would expect of a 40-second exposure (and it was low and washed out by city lights, I didn't use filters), but its characteristic shape is there, and the nebulosity stands out from the stars (after a bit of curves and levels in PS, plus lowering the cyans). So I don't think it's a matter of choosing an "easier" target, there is something definitely odd about your picture. It may be the stacking, without flats the gradients may be dominating the photo. The stars look too red, so as Astro Noodles says, have you colour-corrected the photo? If you post a single photo, it may be easier to see if it's the stacking/processing, or if it is the capture of data that needs improving.

Edit: I have just noticed the mouse pointer in your photo. Is it a screen capture? It probably looks worse than a file saved directly from gimp.

Edited by Felias
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