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.
Thor's Helmet in lrgbhoo. About 24 hours integration. Stars, nebulosity and luminance all processed separately. Shot in suburban Canberra, Australia.
Downsized for posting.
Thanks @mabula-admin, @artem for the kind comments.
I thought I might describe how I created the synthetic luminance, as it is a new technique - for me at least. Might be useful for others.
I started with a normal (drizzled) integration, producing stacked files for each filter (lrgbho). Then I cleared APP and loaded the luminance, Ha and Oiii stacked files as if they lights and told APP that they were all Luminance. Then I stacked these three files using the "maximum" integrate setting (rather than "average" or "automatic") - resulting in the maximum value for each pixel. This gave me a high quality Luminance stack that was very easy to denoise and sharpen. Then I just layered this onto a "rgbhoo" file from the rgb combine tool and it needed very little extra processing. I'm not describing the extra steps where I separated the stars and added them back at the end.
I used to sometimes create a synthetic luminance by selecting "integrate per channel and all" under "multi-channel/filter options", but I always worried that this would average down pixels that were bright in one filter and dark in another. This method seems to work better, although perhaps not for every target.
I'm guessing this technique might even work well for a osc camera, ie by separating the rgb channels and doing a "max" integration to produce a luminance file. I might experiment with that, although I only use osc for widefield.
JC
