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.
Maybe its me, but the HOO formula doesn't seem to be working. I would expect it to ask me (or let me add) Ha to Red, OIII to Blue and to Green. But instead, when I add Red, it prompts to me to add Blue and Green to Red also.  And then when I go to Green and Blue it does the same, its asked me to Add Red/ Blue/ and Green to Green (and then the same 3 to Blue). For example, if i add Green, it will prompt for all Red/ Blue/ Green to be added to it, that's can't be right.Â
What I want it to do is to let you choose HOO, then let you add Ha to Red (and only this), then when you Add Green, prompt you for Oiii, and then when you add Blue, prompt you for OIII.  Or simple just ask you what file for Ha and what file for Oiii, and assigns automatically Ha to Red and Oiii to blue AND green.
Hi Skye @skysong,
Thank you very much for your question.
The HOO formula is for H-alpha and O3 data. So you only want to add H-alpha and O3 channels to such a compostion if you want to work with the preset HOO formula.
I think there is some confusion here. Adding red makes no sense in the sense of red meaning a Red broadbanc channel.
If you load H-alpha and O3, and select the HOO formula, then you can simply assign the H-alpha data to H-alpha if it is not recognized automatically, same for O3. Then is works simple and well.
If you do have Red, Green and Blue broadband data, and want to use the HOO formula, than you need to make this formula yourself. The preset formula of HOO is meant for loading H-alpha and O3 channels for a classic HOO composite.
It could be that I also do not fully understand your question here, so please elaborate then 😉
Mabula
Right, but the metafilter still says Red/ Blue/ Green.  I'm probably using it wrong, or overthinking how it works.  When i got to tool/ combine RGB / formula HOO, then it prompts me for each color Red/ Blue/ Green (meta filters), and I i put Ha, Oii, Oii.  The last one is Red and it goes to Oii, shouldn't Ha go to Red? I'll play with this and see if I can figure it out.Â
Yeah RGB combine on HOO just doesn't seem to work right.  On first Add Channel, i can choose Ha, then it uses Meta Filter Red, and asks me to add three different files to Red, which makes no sense, so I cancel on 2nd two questions (they all add to Red, first one is sufficient). Then I Add Channel again, I choose Oiii, then it uses Green metafilter, and asks me 3 questions again, trying to assign to Green metafilter.  It won't automatically recognize my file has Ha or Oiii in file name. Then if I add another channel, then it matches Oiii to Oiii, but already done by that point, so i just cancel again. So i've pushed Add Channel 3 times, and each time it asks me 3 questions about which files to assign to Red, and 3 questions which to assign to Green, etc., so 9 questions overall.  It should only ask 2 questions (or one if its smart enough to read file names), what's the Ha, and what is Oiii, and just splits those to R, and G/B automatically. Â
I made some progress on this. It seems you have to Integrate to "Hydrogen_alpha" and "Oxygen_III" at first.  When i tried to do was integrate to RED (was actually Ha) and GREEN (was actually Oiii), but then use the RGB Combine tool on HOO to combine them, BUT THE TOOL looks for "Hydrogen_Alpha" specifically in the FITS header (not the file name, and not what you say when you load the file to RGB Combine), it must be in the FITS header to work correctly.Â
Hi Skye @skysong,
Okay yes I see why you got confused here.
Indeed, the TOOL explicitely assumes that you load H-alpha and O3 data to make a HOO composite. If you load data that have H-alpha an O3 in the filter tag of the FITS file, all is easy and smooth.
But, if for some reason, your H-alpha and O3 frames have wrong filter tags, like Red and Green, you need to be aware of that yourself and you can still properly fix that in the RGB Combine Tool.
When you load you Red frame, which is actually H-alpha, APP sees the RED tag in the file's header, so APP offers you automatically to load it as Red, but you must decline that and you must then simply inform the tool that it is not Red, but H-alpha, idem for the Green/O3 file. Then the HOO formula and the calculations will work as expected.
Does it make sense now?
Mabula
