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.
Hi,
I'm working on a very large mosaic (94 frames) and have already integrated each panel/frame and can successfully form the mosaic, though it takes a few days of compute to do so. The problem I am having is that it keeps getting down sampled by a factor of 0.66. I know that's a technical limitation, sadly, so I want to try to minimize the amount of black space around the mosaic and hence reduce the amount it's getting down sampled.
I know I can crop individual frames, but what I want to do is, after registration, define the crop box and have the mosaic be created in that. As an illustration, I've attached a previous iteration of this mosaic along with a red crop box. You'll see how it overlaps with multiple frames in a way that would make it extremely difficult to crop the individual mosaic panels.
Any ideas how I could do this?
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Hi David @dkoslicki and Chester @cheche,
Thank you very much for sharing this issue. At the moment, this is not possible yet I am afraid, but I can see the use case clearly !
You can use the composition mode of crop in 6) integrate, to have a limited field of view of only the reference frame and that is not what is happening here.
So I will add to our todo list to make it possible to crop the whole field of view of the full composition mode 😉
Thank you very much for this.
Mabula
@mabula-admin Awesome! Thank you for the reply.Â
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APP has been by far the easiest to use stitching tool for landscape astrophotography because of its excellent registration and local normalisation(compared to ICE and PTGUI), so this feature would be an absolute game changer for this usecase!
Hi @madula-admin, that's great to hear it's on the todo list! I must say I really appreciate how the APP dev folks continue such a pace of improvements, new features added, etc.

