[Solved] Good LRGB stacks show up as very dark in RGB Combine Tool, even at 30% stretch

Here are image examples to show what is going on. I was hoping that it was an issue with just that M78 stack, but this is from last night of the Horsehead region, and the same result. This is a serious problem and hope that the admins here can address it soon so I can properly process my data.

Images are of the LUM stack at 30% stretch, HA stack at 30% stretch, and the result of the RGB Combine tool with all 4 channels also at 30% stretch. Not good.

Thank you,

Eric

Is it the first time you used NINA by any chance?

And please upload these few frames to our server, we can have a fix ready (maybe) before the next upcoming release. Click here for the server, login and password: appuser

Create a directory with your name + combineRGB issue and upload them into that. Thanks!

@vincent-mod

Vincent

No, it's not my first time using NINA. I captured and stacked and preprocessed several images before this started. The individual channel stacks look great, but when they are combined the issue occurs. My original post on the forum has three images attached to it that demonstrates the issue. They are screen shots only. The frames from the QHY600 stacks are gigantic and I can't practically upload them to the server. Can you please just look at the ones I posted on my original message and see if anything jumps out at you before we proceed with trying to get you some full frames.

Thanks

I can try, the problem is that Mabula is very close to the release of 1.076 and having the data would be the quickest. Otherwise I can't guarantee it'll be fixed before 1.076 (likely very fast afterwards though). How big a a fits for these final integrations?

Vincent

I got remote access to my system at home and am uploading two frames now. A stacked LUM image of M101 and the result of a LRGB combine of all of the M101 data. Please review when they are complete and let me know if anything stands out.

Thank you

Eric

Ofcourse, I'll let Mabula know when the data is available.

@vincent-mod

They are both uploaded and available now.

Thanks

Merci, Mabula is going to have a look at them.

Some notes that may be material to this issue:

1. These were the first data sets collected using the direct driver connection in NINA to the QHY600 instead of the ASCOM driver

2. All of the data sets collected since I went to the direct driver have the same problem. All of the raw data looks very good, but fails to stack using the combine tool in the same way

3. These are the same gain/offset and exposure settings that I have used on this camera for several months

Thank you again,

Eric

I was mistaken. I did capture and process a full LRGB set of data on M81/82 and it processed normally on 1/17. I examined both FITS headers and they are identical other than target details.

Hi Eric @flywaldo and Vincent @vincent-mod,

I am investigating your data and issue now 😉 Thank you for uploading it.

I do know about this issue because it has been reported before and I have experienced it myself on some data setes as well.I will report back later on my findings and if I can fix this problem for the next release.

Mabula

Hi Eric @flywaldo,

To be able to properly solve this issue, I need to test this on your linear composite data. You have sent me already stretched data:

Pinwheel-combine-RGB-tool-image-St.fits

I can see that the stretch isn't looking good, but I can't use this stretched data for testing 😉

Can you send me the linear composite data? Or even the linear data integrations used to create the entire composite, like the L, Ha, R, G, B layers?

And if you could send me the linear composite data of the HorseHead nebula as well, that would be most helpfull.

Thanks,

Mabula

Hi Eric @flywaldo and Vincent @vincent-mod,

I have some data that shows the same problem. I think I have found the problem and I am fixing it. This is H-alpha & OIII data of the Tarantula Nebula:

Ha, OIII, RGB Combine HOO in APP 1.075 (BAD), RGB Combine HOO in APP 1.076 (GOOD)

I will do some additional testing and work on the RGB COmbine tool for the next release, I will add the possibility of adding 7 layers, it is now limited to 6, 7 would be needed for a LRGB SHO composite.

And I will add the possibility to influence how all channels are normalised to each other. Now the backgrounds are normalized additively, multiplicatively would be better for most datasets.

The tool does not normalize for dispersion at the moment, I think this should be added as well...

Kind regards,

Mabula

@mabula-admin @vincent-mod

Mabula,

I will send you the raw stacks of the LRGB channels for two different targets. I'm heartened to hear that you have seen and experienced this before and I'm not special. It will take a while to upload all of those files, but they will start soon.

Thank you,

Eric

@mabula-admin

That's great news that you found a solution to this!

I'm uploading the data stacks for the Horsehead and Pinwheel now for your testing purposes to make sure it all works.

I'll just go ahead and keep collecting photons until the next release. I'm still in the testing and break in phase with this awesome camera so I have plenty of work to do with different gain/offset settings and calibration settings to do in the meantime.

Thanks,

Eric

@mabula-admin

I did a stack of data without any calibration files and the RBG combine worked normally. I hope that helps in your search for a solution.

Hi Eric @flywaldo ,

Here are image examples to show what is going on. I was hoping that it was an issue with just that M78 stack, but this is from last night of the Horsehead region, and the same result. This is a serious problem and hope that the admins here can address it soon so I can properly process my data.

Images are of the LUM stack at 30% stretch, HA stack at 30% stretch, and the result of the RGB Combine tool with all 4 channels also at 30% stretch. Not good.

Thank you,

Eric

 

I have definitely found the cause of the problem. All data is working perfectly now. The problem had to do with data range adjustments internally in APP and caused calculations on creating the composite to be messed up and consequently ugly stretches...

Both your data sets work fine now 😉

I have also added additional functionality to the RGB Combine tool, the data can bow be normalized, just like in 5) Normalize. And.. I am trying to improve speed of the tool. The frames of your new camera are huge indeed ! Great data by the way, beautiful 🙂

Below image is only with 15% ddp preset...

Cheers,

Mabula

@mabula-admin

That is outstanding news sir, thank you. The data that comes out of this camera combined with the mount and optics it works with are really spectacular. Your software has allowed me to bring my processing to the next level these past several years, so thank you very much!

Will this fix be available in 1.076? And do you have an ETA for that release?

Good evening,

Eric

Thank you Eric for pointing out the issue 😉 @flywaldo,

Yes, the fix will be in APP 1.076, I am about to release a first Beta of APP 1.076 which will include it as well.

I think APP 1.076 stable will released early the beginning of February. The Beta might be available in 2-3 days.

Kind regards,

Mabula