Struggling with image background with new CMOS camera

Questions and answers about processing in StarTools and how to accomplish certain tasks.
Mike in Rancho
Posts: 1141
Joined: Sun Jun 20, 2021 10:05 pm
Location: Alta Loma, CA

Re: Struggling with image background with new CMOS camera

Post by Mike in Rancho »

Paul I've had that kind of noise quite a bit. Your eventual result did a good job on it though.

For me, what helps to avoid it is random dithering (I just learned an important lesson from using spiral dithering), lots of integration, and only AutoDev stretching to the amount the overall data actually warrants, even though that sometimes seems like the main target is understretched.

Background problems can also be de-emphasized using special settings in AutoDev and Contrast, and DimSmall in SS.

Lastly, if there's still a problem existing after denoise and final touch-ups, and you don't want to go back and start over, I've found that a FilmDev at the very end with adjustments to Gamma and Skyglow can act as sort of an "unstretcher." What I look for usually is to make the histogram's left sided hump a bit more vertical.
ionia23
Posts: 62
Joined: Fri Jul 16, 2021 7:39 pm

Re: Struggling with image background with new CMOS camera

Post by ionia23 »

Holy Toledo, I was already blown away by the first image. The second one deserves a place in a gallery.

It's also a great lesson to me "It is much easier to improve good data than repair bad data."
PaulInNorthMichigan
Posts: 35
Joined: Sat Aug 08, 2020 5:44 pm

Re: Struggling with image background with new CMOS camera

Post by PaulInNorthMichigan »

Mike in Rancho wrote: Mon Jul 26, 2021 6:16 pm Paul I've had that kind of noise quite a bit. Your eventual result did a good job on it though.

For me, what helps to avoid it is random dithering (I just learned an important lesson from using spiral dithering), lots of integration, and only AutoDev stretching to the amount the overall data actually warrants, even though that sometimes seems like the main target is understretched.

Background problems can also be de-emphasized using special settings in AutoDev and Contrast, and DimSmall in SS.

Lastly, if there's still a problem existing after denoise and final touch-ups, and you don't want to go back and start over, I've found that a FilmDev at the very end with adjustments to Gamma and Skyglow can act as sort of an "unstretcher." What I look for usually is to make the histogram's left sided hump a bit more vertical.
Mike; I thought that I submitted a reply yesterday but I guess it didn't take.

Thank you for your ideas for obtaining better images.

I know that my new camera will be an adjustment to get past some of the hurdles but just having a glimmer of success goes a long ways in keeping the optimism in the upswing.

I will certainly want to be testing out your suggestions.

As far as the dithering that I use, it is within the Ekos software. I am dithering with every image but I am not sure whether I can randomize the dither.

Yes; I am gaining a little of an idea in not over applying the AutoDev. The noisy background should have been apparent the 1st time, but in just starting it was hard to establish whether that would have been normal during the process and if it could later be removed.

I can always look back to this thread for trying out some ideas and observing their effects.

I have really yet to determine whether the setup settings that I've tweaked have made a positive impact yet, but should be getting there soon.

I certainly appreciate ideas for better processing!
PaulInNorthMichigan
Posts: 35
Joined: Sat Aug 08, 2020 5:44 pm

Re: Struggling with image background with new CMOS camera

Post by PaulInNorthMichigan »

ionia23 wrote: Tue Jul 27, 2021 12:14 am Holy Toledo, I was already blown away by the first image. The second one deserves a place in a gallery.

It's also a great lesson to me "It is much easier to improve good data than repair bad data."
:greetings-clapyellow: Thanks so much for your positive feedback.

I can still see my stacking/processing flaws, but I am still happy looking at the image as my desktop at work.

Best of luck in your imaging!
hixx
Posts: 250
Joined: Mon Sep 02, 2019 3:36 pm

Re: Struggling with image background with new CMOS camera

Post by hixx »

Lastly, if there's still a problem existing after denoise and final touch-ups, and you don't want to go back and start over, I've found that a FilmDev at the very end with adjustments to Gamma and Skyglow can act as sort of an "unstretcher." What I look for usually is to make the histogram's left sided hump a bit more vertical.
Hey Mike,
the FilmDev as a final touch up is an awesome tip! :bow-yellow:
I will make sure to include this in the next version of the inofficial manual
clear skies,
jochen
Mike in Rancho
Posts: 1141
Joined: Sun Jun 20, 2021 10:05 pm
Location: Alta Loma, CA

Re: Struggling with image background with new CMOS camera

Post by Mike in Rancho »

hixx wrote: Wed Jul 28, 2021 5:54 pm Hey Mike,
the FilmDev as a final touch up is an awesome tip! :bow-yellow:
I will make sure to include this in the next version of the inofficial manual
clear skies,
jochen
Thanks Jochen,

I just fiddle with things though, so we'd probably need an endorsement from Ivo to make sure I'm not mucking things up with that little trick. It seems to help though when I realize at the end I've gone too far, particularly on displays that are brighter than normal (like mobile).

Changing of gamma though makes me think of it as sort of a final bite at the apple for a quasi-SS. Except you can also use Skyglow as a counterbalance and see the little histogram as well.

Going into FilmDev at the very end was something I read out there that some would do, but just to bump up Skyglow in order to avoid harassment from the blackpoint police. :lol:

Though I believe Ivo has explained that Skyglow is just a pedestal anyway. But I then started playing with the gamma and seeing how it changed the image and the graph.

A somewhat similar, but more limited, effect can be seen if you return to Color module at the very end. The presets are such that the image appears identical, except that the highlight and shadow saturation levels are at 9.9 instead of full, which just takes out a wee touch.
Burly
Posts: 387
Joined: Mon Aug 31, 2015 7:06 am
Location: Northamptonshie uk

Re: Struggling with image background with new CMOS camera

Post by Burly »

Apparently Darks are mandatory with the zwo 1294 (Amp Glow) , try stacking with darks flats and bias or Dark Flats but not both .

Dave
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