My first ever astrophoto: NGC7000 North America nebula

[Bluesboystig]

Hi everyone, super excited, got my first session last night and went for NGC7000. Needless to say, I have a shedload to learn and a lot of pick up for processing, but wanted to share with you and ask for any advice, comments, suggestions etc. 

Equipment used: Star Adventurer GTI, WO z61 with flat61, Canon eos2000d unmodded, Optolong L-Pro. 86 lights (55s each) for a total of 1h15mins of integration time, 15 darks, 15 flats, 15 bias frames. (I think I have some dust on the sensor, I see there are some circular artefacts in the image). Bortle 6 sky in Berkshire

FIT file at the bottom

NGC7000.fit

Edited September 5, 2023 by Bluesboystig

[Mark2022]

Nice job. I like the natural colours from the unmodded camera. The Cygnus wall stands out very well and I don't notice any artifacts. Nice round stars too. Then again, I'm no  connoisseur. When those photos are on the back of your DSLR there's a buzz that  those outwith the astro community don't understand.  When you then stack an process and get a result that's pleasing  to you, there's the next buzz. From then on there's a lot of 'hate speech' you should be locked up for, against clouds! What did they ever do to you?

[Bluesboystig]

Thanks @Mark2022! I'm quite happy with the result, even though I think I overdid it with the processing, it looks a bit noisy to me. I might try remove stars to edit the nebulosity and re-apply them with starnet (need to learn how to do all that but hey). Also, I think that just over 1h of integration time is not that much time (plus a 70% moon). Lots to learn for sure!

[carastro]

That's very good for a first image.  Much better than my first attempts.

[AstroMuni]

1 hour ago, Bluesboystig said:

Hi everyone, super excited, got my first session last night and went for NGC7000. Needless to say, I have a shedload to learn and a lot of pick up for processing, but wanted to share with you and ask for any advice, comments, suggestions etc. 

A great shot. Welcome to the dark side 🙂 What software did you use to process the images?

[Bluesboystig]

Thanks @AstroMuni! I hope the force is strong in me  I should have mentioned (rookie mistake):

• Stacked in Siril, and I used Siril for background extraction, gradient removal, green noise removal and some stretching as well. I used the deconvolution tool as well, but I think I did something wrong there as I can see funky stuff around stars when zooming in
• GIMP: some more stretching, contrast, saturation

Not sure how much more signal can be extracted from the data I have, I don't want to push the processing too hard to get colours and in the process create a lot of noise. 

[AstroMuni]

6 minutes ago, Bluesboystig said:

Not sure how much more signal can be extracted from the data I have,

You could post your unprocessed FITS file here (just after stacking) and others can show you what they can get out of it. Thats what I tend to do when in doubt if there is more in my image.

[Bluesboystig]

Here's the stack @AstroMuni if you or anyone else fancies a go at it, I'd very much appreciate it. 

result.fit

[Paul2019]

Looks great, only feedback I can offer is to not use the l-pro filter for non broadband targets. For ha you want the l-enhance, l-extreme or l-ultimate. I suspect the l-pro is why you have those circular artifacts too. 
 

stars are nice and round so your doing something right! Don’t forget to share your next one too 😄

[WolfieGlos]

For a first image that’s great! Especially for only 1.25 hours. Stars are nice and round and have good colours. What ISO did you use for 55s subs? 

You can add more time to bring out more detail and help to reduce noise.

Taking it a step further, you could try reducing the stars using Starnet allowing the nebulosity to shine through. All part of the learning curve! 

Edited September 5, 2023 by WolfieGlos

[Bluesboystig]

12 minutes ago, WolfieGlos said:

For a first image that’s great! Especially for only 1.25 hours. Stars are nice and round and have good colours. What ISO did you use for 55s subs? 

You can add more time to bring out more detail and help to reduce noise.

Taking it a step further, you could try reducing the stars using Starnet allowing the nebulosity to shine through. All part of the learning curve! 

Thanks! I used ISO 1600, it seemed like a good option. Definitely happy as a first attempt for sure, I was trying to understand how to use starnet so definitely something to get to grips with!

[Clarkey]

If it was my first image I would be delighted. Well done!

[WolfieGlos]

59 minutes ago, Bluesboystig said:

Thanks! I used ISO 1600, it seemed like a good option. Definitely happy as a first attempt for sure, I was trying to understand how to use starnet so definitely something to get to grips with!

If you do start to learn it, I’d currently recommend using it in the standalone version. I use the GUI rather than the command line version.

I find the one in Siril loses the star transparency, especially when recombining, and they have a see-through appearance. Give it a go, but that’s just my experiences with it.

[The60mmKid]

This is really lovely. Congratulations on such a beautiful first photo!

[Padraic M]

Great shot, and well done! 

I don't use Deconv much, as if the image has any level of noise tends to will emphasise it. Something to come back to later when you have very smooth images.

[Bluesboystig]

Thanks @Padraic M and @The60mmKid! 
If anyone knows what those circular artefacts are I’d love to know.. maybe something on the sensor/scope/filter? Or maybe while shooting flats there was something on the white t-shirt I used? Anything else? 

[alacant]

20 hours ago, Bluesboystig said:

Canon eos2000d

Hi

Just over an hour?  Well done. The star field gives nice structure.

2000d? so iso800, dither at least 5 pixels between frames, lose the dark and in camera bias frames and simply subtract the offset -Canon use 2048 on later models- during calibration.

The flat frames don't seem to have corrected. This may explain the dark blobs and vignetting.

Cheers and HTH

Edited September 6, 2023 by alacant

[Bluesboystig]

24 minutes ago, alacant said:

Hi

Just over an hour?  Well done. The star field gives nice structure.

2000d? so iso800, lose the dark and in camera bias frames and simply subtract the offset -Canon use 2048 on later models- during calibration. siril makes this easy.

The flat frames don't seem to have corrected, which probably explains the dark blobs and vignetting.

Cheers and HTH

Thanks @alacant. Do you mean I should use ISO800 going forward and not take darks and bias frames? Also, not sure what subtracting the offset means. Any resources you could point me to so I can learn? Thanks so much!

 

[alacant]

8 minutes ago, Bluesboystig said:

I should use ISO800 going forward and not take darks and bias frames?

Yes.

8 minutes ago, Bluesboystig said:

Also, not sure what subtracting the offset means

Documentation:

https://siril.readthedocs.io/en/latest/

HTH

 

Edited September 6, 2023 by alacant

[Bluesboystig]

Another rookie question: can I (I think so but not sure how) get more subs let's say tonight and add them to the stacked file/stack everything together again? If so, how (using Siril)? How do I add flats from different sessions in case? Sorry if it's a bit of a dumb question.

[alacant]

 

1 hour ago, Bluesboystig said:

stack everything together

- Process the second night as you have the first but stop after calibration.
- Create an empty working folder and set siril to that folder.
- Conversion > +
- Select the pp files from the first night
- +
- Select the pp files from the second night
- Enter a name for the new sequence
- Convert
- Register
- Stack

[WolfieGlos]

1 hour ago, Bluesboystig said:

Another rookie question: can I (I think so but not sure how) get more subs let's say tonight and add them to the stacked file/stack everything together again? If so, how (using Siril)? How do I add flats from different sessions in case? Sorry if it's a bit of a dumb question.

What alcant has said is correct, but there is also another way.

You can stack the second nights images together (using a script or otherwise), to create a second stacked file. You can then "stack the stacks" using a second script. Depending where you look online and who you ask, some people frown on it and others use it. Personally, in my limited experience, I've found no issues with it. Give it a try and see what you think.

On this website https://free-astro.org/index.php?title=Siril:scripts there are some freely available scripts to download, and to do this you need the "OSC Preprocessing without DBF" - i.e. stacking without darks, biases or flats. After downloading and placing it in the scripts directory: 

1) Create a new working directory

2) Create a new sub-directory in the new one called "lights"

3) Place both stacked files into the lights directory (you might like to rename the files, I usually call them "result_night_1", 2, 3, etc.

4) Set Siril's working directory to the new one.

5) Run the WithoutDBF script.

Here's one that I'm currently doing, gathered 3 nights of data so far this week. I've had some images with 7 nights worth of data, limited by the short nights or clouds, etc.

 

HTH

 

[Bluesboystig]

1 hour ago, WolfieGlos said:

What alcant has said is correct, but there is also another way.

You can stack the second nights images together (using a script or otherwise), to create a second stacked file. You can then "stack the stacks" using a second script. Depending where you look online and who you ask, some people frown on it and others use it. Personally, in my limited experience, I've found no issues with it. Give it a try and see what you think.

On this website https://free-astro.org/index.php?title=Siril:scripts there are some freely available scripts to download, and to do this you need the "OSC Preprocessing without DBF" - i.e. stacking without darks, biases or flats. After downloading and placing it in the scripts directory: 

1) Create a new working directory

2) Create a new sub-directory in the new one called "lights"

3) Place both stacked files into the lights directory (you might like to rename the files, I usually call them "result_night_1", 2, 3, etc.

4) Set Siril's working directory to the new one.

5) Run the WithoutDBF script.

Here's one that I'm currently doing, gathered 3 nights of data so far this week. I've had some images with 7 nights worth of data, limited by the short nights or clouds, etc.

 

HTH

 

This is really helpful, thank you very much! I guess I'll have to try and be as precise as possible with framing again?

[Padraic M]

15 hours ago, Bluesboystig said:

Thanks @Padraic M and @The60mmKid! 
If anyone knows what those circular artefacts are I’d love to know.. maybe something on the sensor/scope/filter? Or maybe while shooting flats there was something on the white t-shirt I used? Anything else? 

Play around with the calculators on this website: https://astronomy.tools/calculators/dust_reflection_calculator

Those spots are reasonably well defined, so not very far from the sensor. Definitely not something on the t-shirt. Based on your camera pixel size, and the focal length and aperture of your scope, the calculator quotes a distance of 2.7mm from the sensor. Does that sound like there's dust on the Optolong???

Anyway, rather than trying to clean your filter (you risk scratching it, and you will just get more dust on it anyway), getting proper flats will calibrate out any dust or dirt anywhere in the imaging train. Maybe just a quick blow from an air blower would also help.

[Bluesboystig]

10 hours ago, Padraic M said:

Play around with the calculators on this website: https://astronomy.tools/calculators/dust_reflection_calculator

Those spots are reasonably well defined, so not very far from the sensor. Definitely not something on the t-shirt. Based on your camera pixel size, and the focal length and aperture of your scope, the calculator quotes a distance of 2.7mm from the sensor. Does that sound like there's dust on the Optolong???

Anyway, rather than trying to clean your filter (you risk scratching it, and you will just get more dust on it anyway), getting proper flats will calibrate out any dust or dirt anywhere in the imaging train. Maybe just a quick blow from an air blower would also help.

That's so interesting, I didn't know about that calculator! thanks for the help! Hopefully it's just some dust on the filter, and not something to worry about...