2026-10-09 APP 2.0.0-beta48 has been released !
This is mainly a bug fix release for the reported bugs in beta47. In addition it has a significant User Interface performance improvement noticable when you need to process 1000s of images in APP.
2026-10-03 APP 2.0.0-beta47 has been released !
This is a very big release... many code optimizations/rewrites, many parts of APP are much faster and more precise, especially star analysis and registration are much faster ! Big mosaics will go much faster 🙂
And we introduce a new preview filter, which includes the new Adaptive Deep Sky Stretch and a General Levels Stretch, this has been long over due. The old preview filter (the panel on the right side to stretch and preview your data) has not been updated for a couple of years and it is a critical part of any APP session.
Adaptive Deep Sky Stretch or ADSS is a much more intuitive stretch algorithm. It is also color preserving (which is a great new addition in itself ! ) which means that the highlights are no longer bleached, color is maintained from the linear data while stretching. You can simply stretch your data using the sky background level and signal width sliders which work much easier and more intuitive. You no longer need to fiddle with the old complicated sliders with zoom buttons. All the zoom buttons for the sliders are made redundant. And you can enter slider values in the slider value fields yourself. I will make a youtube video in the coming days to explain and fully introduce ADSS. Once the video is ready, it will be highlighted on the forum.
RGB Combine upgrade !. The RGB Combine Tool has been rewritten mostly. The tool is faster and easier to use and most importantly, the Luminance slider to inject a luminance channel or channels into the RGB composite is now working correctly. It no longer bleaches the RGB colors. Combined with the new ADSS preview, you will get much better and easier great composites with great color! I will also explain this in a new youtube video.
I try to process my data from m51.
My files are R G B and HA from OSC
Everything going normal before Star Color Calibration after this my data taking a reddish color and i cant get over it ...
This is Before star Color
And this is after
Any Help will be appreciate it ...
If someone want i can upload my data to check it ...
Many thanks.
Maybe you have a dark frame problem like me although your results don't look so bad - mine appeared to lose all red content. If things don't go as expected, analyze your darks, flats and bias frames. Do an integration with only the lights and then successively do more integrations while adding one of the calibration frame types each time. Good luck
Thanks for the reply mate ...
My calibration frames are from my library and are check it ...
I still cant understand why the star color calibration effects on galaxy or in nebulosity ...
Normal must effect only in star color ...
If you want i can upload my files to give a try ...
Hi Stratos, My understanding was that the star colour calibration was using stars to calibrate the white balance of the whole image. Your image looks like its not lacking in colour - maybe too much. Do you have a UV/IR cut filter? Without one you will get too much red from the IR spectrum above Ha.
My R G B data is from L pro filter that have uv-ir cut ...
my Ha data is extract from L enhance filter so must not be a problem...
Is this your first time with those filters? I think some of them can affect the normal colour so maybe you should not do star colour calibration. Narrow band imaging will not give you true colour - although I think the L-Pro is pretty balanced, but not L-enhance. You kind of have to mix and match the colours to give something nice looking like the Hubble palette. I think you can skip star colour calibration.
Actually, I think you need to do multichannel/filter processing and then do combine RGB Tool at the end.
Its not first time that i using these filters ... I shoot almost exclusively with them ... from L enhance I took only ha so can’t unbalance my rgb ...
@astrogee I Use this workflow my friend for this kind of data ...
That looks awfully complicated. I think APP will do it all with multichannel processing by adding each RGB and Ha-OII - tab 0 has Ha-OIII algorithm, which I think you can add to the RGB with RGB tools at the end. I've done narrow band but not OSC narrow band, which I think has been supported very recently, since that posting.
We will wait to see what moderators will answer mate ... I’m very interesting too see how will work the star color calibration...or if I must skip it ...
It's not too complicated when you follow along. APP can't normalize mono data with broadband RGB, so it's better to do this separately, making it nice and clear as well I think. You can produce all mono data at once and create the integrations. Then the RGB and then you can use that data in Combine RGB to mix in the mono data.
@vincent-mod
Thanks for reply Vincent !!!
But how can I do it separately ?
Have any workflow or some instructions ? I use this workflow but seems don’t work good ...
So where does it go wrong for you in that workflow?
@vincent-mod
In beginning of post have two pictures with before and after star color calibration...
Do you want to upload my files to check them ?
Ah sorry, I didn't look close enough there. So, those frames are the result of RGB Combine right? Combining RGB with the H-Alpha.. did you select only stars or also the galaxy itself? I think only stars would work better.
@vincent-mod
Yeah my files are RGB and HA combine... everything work great before star color calibration after this all meshed up ... I boxed only stars for calibration not the galaxy ...
Mmm, so you can ofcourse skip the star calibration then as that already looks good. But if you want I can have a better look as well, you can upload that one file to our server if you want, login/password: appuser
@vincent-mod
Sure !!! I will upload the RGB HA files
in server to check them...
I will send you here in post the details of
folder ... thank you so much Vincent...
@vincent-mod
I uploaded Vincent ...
The folder name is Stratos Sinathis M51
Thank you ...
The mean differences between the channels R,G,B are from 2.53 to 3.02, too low. So RGB il almost white. The mean difference between Ha and the other channels is ~ 11.12, 4 times more.
The rgb data is split channels from Broadband filter With osc camera zwo 294 and the filter is L pro. The Ha data is extract from L enhance narrowband filter ... this is the workflow that I following> https://www.astropixelprocessor.com/community/tutorials-workflows/combining-r-g-b-with-ha-oiii-data-using-an-optolong-l-enhance-filter/
Yes that could be one of the issues. You can always lower the amount of Ha you use for instance. Mixing it 50-50.
I'll have a look today.
@vincent-mod
ok Vincent... I will waiting your processing...
Thanks again ...
So here's what I got. I selected stars on the left hand side and another big box underneath the galaxy. It seems that the filters do change the broadband data a bit, so I tweaked the slopes a little bit to have the line go through the population a bit better (that's the white line in the correction graphs). I also made a comparison with 50% Ha into the red and 33% Ha into the red. Before I combined all panels, I first did light pollution correction to have a nice background, all similar to each other.
This is right after combination with 50% Ha;
This is with color correction and a tweaked slope of the line. I also lowered both Magenta - Green slider to about -0.05 to remove a bit of green cast;
Next up, 33% Ha into red;
And with tweaked slopes;
Saturation was upped a bit to 0.19. Is this more to your liking? It does seem the colors could be more pronounced, what was the total integration time?
@vincent-mod
Hello Vincent ...
For sure is better than my processing ...
the total time is about 10 hours ... 7 rgb and 3 Ha
@vincent-mod
I think that before star color calibration you still get better result ...
What you think ?
No, personally I don't think so. That first image looks very dull, color wise. So there seems to be an offset, created probably by the filters.
@vincent-mod
I can’t have good view from screenshots ... plz when you finish upload it in server to check it ...
Ofcourse, I uploaded the 33% Ha into Red final stretch in your directory on the server. The file is called "combine-RGB-image-33Ha-cbg-St.fits"
