My First Ever Galaxy Images/Awful!

[wesdon1]

Hi all. I did my first ever galaxy imaging a few nights ago. I only manage just over 1 hour of integration. I did all my calibration frames, and stacked them in DSS. But again when it came to processing, which in this case I used GIMP, I just could not get the background sky to darken, and also couldn't get the galaxies themselves to "pop" or be brighter in the image, relative to the night sky background. I have tried several online tutorials, but no matter what I do, I just seem to be stuck on this one huge issue, getting the night sky background darker!? So I reverted to my usual bailout option, which is simply to do a super basic processing of image in Windows 11 Photo Editor, which allows you to crop, and adjust basics like brightness, contrast, tint, etc etc etc. It's really getting me down...

If anyone has a simple and easy to follow routine for getting background night sky darker in processing then I would be profoundly grateful!

Target - LEO Triplet

Lights - 62 x50 sec

Darks - 62 x 50 sec

Bias - 20 x 1/4000 sec

Flats - 20 x 5 sec 

ISO - 1600

Telescope - ALTAIR Lightwave 66/400 ED

Mount - Skywatcher HEQ5 Pro

Camera - Canon EOS T1i DSLR

Filter(s) - Optolong L-Pro

*Unguided

I have included both the raw stacked image, and then the "processed" image after doing a super basic processing in Windows 11 Photo editor. ( for reference, The processed image has a number 7 at very beginning of file name, and processed image has the number 2 at very beginning )

 

 

[vlaiv]

Redo stacking but without darks.

Your flat calibration has failed as well for some reason. Are you using viewfinder cover for your DSLR when shooting long exposures?

[Clarkey]

35 minutes ago, wesdon1 said:

I did my first ever galaxy imaging a few nights ago. I only manage just over 1 hour of integration.

I think you need to lower your expectations slightly with only an hour of imaging. Decent galaxy images will take hours of integration in most cases. Check your calibration frames and add more time.

[wesdon1]

1 hour ago, vlaiv said:

Redo stacking but without darks.

Your flat calibration has failed as well for some reason. Are you using viewfinder cover for your DSLR when shooting long exposures?

Hi, thanks for replying/helping.

No I have never thought to cover the viewfinder while imaging, but I think you've hit on a good point there, because I have extremely bright street lights shining onto back of camera/into the viewfinder when imaging, so some of that light could well be getting onto my cameras sensor and "blowing out" the subs? I'll definitely remedy that issue next time and see how that changes my subs, thanks.

I'll redo the stacking without darks, and see if it helps, thanks. 

Thanks again for helping, I'll update the post after doing suggested things, and let you see if anything helps, thanks.

[wesdon1]

1 hour ago, Clarkey said:

I think you need to lower your expectations slightly with only an hour of imaging. Decent galaxy images will take hours of integration in most cases. Check your calibration frames and add more time.

Thanks for advice/help. I will try out some different things and see how I get on. Thanks again, I really do appreciate it.

[vlaiv]

44 minutes ago, wesdon1 said:

so some of that light could well be getting onto my cameras sensor and "blowing out" the subs? I'll definitely remedy that issue next time and see how that changes my subs, thanks.

Even small amount of light can mess up your calibration, so it's a good idea to cover the view finder.

There is special rubber cap on the strap of your camera that serves this purpose

[carastro]

I think you flats were too long @ 5Secs with a DSLR.  You need to see what the histogram says, and adjust the length to get the histogram about 1/3 to 1/2 way across i.e,. 1/3 well depth.

Otherwise it is a good first image, much better than I got at the beginning.

Carole 

 

[carastro]

I did a quick "fix" on your image above in Photoshop, using gradient exterminator:

 

[Paul M]

Yup, better than my first effort too.

In fact, it's nearly as good as my current efforts...

It's nice to showcase your work, however it might turn out. It gives others confidence in their efforts too!

 

Edited March 25, 2023 by Paul M

[carastro]

It's by showing what you have done and getting advice from more experienced imagers that you learn.

Carole 

[alacant]

21 hours ago, wesdon1 said:

easy to follow routine for getting background night sky

Hi

Nice shot. The galaxies are clearly visible.

The 500d doesn't respond well to either dark or in-camera bias frames, the latter being essential to calibrate the flat frames correctly. 

So... lose the dark and camera bias altogether. Instead, simply subtract the offset. On older Rebels, this is 1024 [1]. You may want to have a look at Siril to do the calibration, the stacking and the processing afterwards.

Oh, and just keep adding frames. The more you add, the easier it will be to process.

Cheers and HTH

[1] A long time since we've seen a T1i  so not sure if the 15mp sensor was at the changeover to an offset of 2048. It's just a few moments to try the other value if the first doesn't work.

 

Edited March 26, 2023 by alacant

[Ratlet]

If memory serves when you would normally put in the address for you bias, just type

=2048

Or 1024 to manually set the bias.

[alacant]

35 minutes ago, Ratlet said:

manually set the bias

Sorry, yes. I should have explained: 

[rickwayne]

Flat darks would also be an option, no?

If you can figure out a way to do so unguided, dithering would be a plus.

You might also get a sharper look if you focus using a Bahtinov mask. It's not very far off, but I think it could be closer.

I'd show you what "awful" picture of a galaxy looks like but people might be eating while reading this and so I'd better not. Trust me, I've worse than this.

[alacant]

9 hours ago, rickwayne said:

Flat darks

Any type of dark frame on an eos is bad news.

9 hours ago, rickwayne said:

I'd show you what "awful" picture of a galaxy looks like

I'd be delighted to help you out with more contributions if necessary.

Edited March 27, 2023 by alacant

[wesdon1]

On 25/03/2023 at 15:06, vlaiv said:

Even small amount of light can mess up your calibration, so it's a good idea to cover the view finder.

There is special rubber cap on the strap of your camera that serves this purpose

oh wow I never even realised/noticed there was a special covering for viewfinder!? Thanks so much!

The weather hasn't allowed me to try out new ideas that you so kindly gave me recently, but as soon as the weather allows, I can't wait to get back out n try! Thanks!

[wesdon1]

On 25/03/2023 at 15:43, carastro said:

I did a quick "fix" on your image above in Photoshop, using gradient exterminator:

 

Hi @carastro. Your post has the words behind the image, unfortunately. But I think I get the gist of what you were saying. Thanks Cara, I'm taking yours and everyone's advice and inspiration and really nailing this issue! 

[wesdon1]

On 25/03/2023 at 15:09, carastro said:

I think you flats were too long @ 5Secs with a DSLR.  You need to see what the histogram says, and adjust the length to get the histogram about 1/3 to 1/2 way across i.e,. 1/3 well depth.

Otherwise it is a good first image, much better than I got at the beginning.

Carole 

 

Oh right? I never thought of that Cara? I'll check Histograms, and reduce my flats duration if the histograms are out, like you so kindly suggest. Thanks so much Cara, people would be lost without the advice and support of others on here.

[wesdon1]

On 26/03/2023 at 10:33, alacant said:

Hi

Nice shot. The galaxies are clearly visible.

The 500d doesn't respond well to either dark or in-camera bias frames, the latter being essential to calibrate the flat frames correctly. 

So... lose the dark and camera bias altogether. Instead, simply subtract the offset. On older Rebels, this is 1024 [1]. You may want to have a look at Siril to do the calibration, the stacking and the processing afterwards.

Oh, and just keep adding frames. The more you add, the easier it will be to process.

Cheers and HTH

[1] A long time since we've seen a T1i  so not sure if the 15mp sensor was at the changeover to an offset of 2048. It's just a few moments to try the other value if the first doesn't work.

 

Thanks so much @alacant. I will indeed do what you suggest, thanks! I've received a ton of brilliant ideas and advice which will really help me get to grips with my issues! Thanks so much, I'd be lost without these places and the people who pass on their experiences and knowledge! priceless! 

[wesdon1]

On 25/03/2023 at 19:54, Paul M said:

Yup, better than my first effort too.

In fact, it's nearly as good as my current efforts...

It's nice to showcase your work, however it might turn out. It gives others confidence in their efforts too!

 

Thank You for such kind words! Maybe I need to lower my ambitions a little until I'm multi-year experienced!? ( I'm roughly 4 months in to my astrophotography journey ) If I'm completely honest and self critical, I am looking at images of DSO's that have been done by people with many years of astrophotography experience, and judging my own work by that. It's silly and impatient, I think...

[wesdon1]

On 26/03/2023 at 16:22, alacant said:

Sorry, yes. I should have explained: 

LOL Thanks I was just about to ask what that meant! LOL. Thanks so much, you and many others have been a life saver, and I am eternally grateful.

[edarter]

23 hours ago, wesdon1 said:

Thank You for such kind words! Maybe I need to lower my ambitions a little until I'm multi-year experienced!? ( I'm roughly 4 months in to my astrophotography journey ) If I'm completely honest and self critical, I am looking at images of DSO's that have been done by people with many years of astrophotography experience, and judging my own work by that. It's silly and impatient, I think...

I dont think you are alone with doing that. I'm massively self critical and compare my results to those with way more experience and better kit. Very easy to get in to a spiral of frustration then. Just be mindful of it and keep in mind its just a hobby and should be fun.... otherwise why are you doing it.

Ed

[wesdon1]

8 hours ago, edarter said:

I dont think you are alone with doing that. I'm massively self critical and compare my results to those with way more experience and better kit. Very easy to get in to a spiral of frustration then. Just be mindful of it and keep in mind its just a hobby and should be fun.... otherwise why are you doing it.

Ed

@edarter You make some very good points there. The biggest one is keeping it fun, otherwise as you correctly point out, if it's not fun then what's the point! 

*Just a quick update, I have been off work today so I've been practicing my data processing in Siril. I have never used Siril before, but I'm so glad I tried it out because I've FINALLY got to grips with darkening background and increasing the brightness of my Galaxies! ( I have put GIMP software to one side for a while, while I learn how to process images better with Siril, which for me personally, seems so so much easier to understand learn!? ) I'm now learning how to adjust colour balances/saturation etc and I'm feeling so much more hopeful of my future Astro-abilities! LOL. I will post my updated re-processed Leo triplet later today or tomorrow after work. Thanks again for your advice and encouragement, I really am very grateful to you and others who have helped me! 

[wesdon1]

Hi again all. I am very pleased to report, I have now learned a lot more after all of your very kind advice, and I've spent my day off work practicing my processing, but instead of using GIMP, I've opted for SIRIL, which I'm finding magnitudes more understandable to use, for me personally. Here is my latest processed image of LEO Triplet. The sky background is darker ( yayyy!! LOL ) and I've cropped and rotated it, just for personal taste. This is only a relatively quick processing, and I'm sure with more processing, I could imp[rove it further still, but I think it's much better than the original, and I'm both relieved and pleased I am now finally getting to grips with processing.

May I say again a HUGE thank you to everyone who so kindly took the time to advise me on the best way forward. I cannot thank you all enough! It goes without saying that if ever any of you need my help ( highly doubtful, I reckon! LOL ) then I'm here for you! Thanks!

Wes.

[Clarkey]

Well done - that looks much better. At the end of the day, the data capture is the 'easy' bit - the processing is the thing that takes time to master. I am only 3 years into my AP journey, and I still consider myself a novice when compared to many others.  With longer integration times there is no reason why you shouldn't get some excellent results. Keep it up!