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.
Hello!
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I am curious how APP works with suboptimal images.
I just did my first long exposures when trying my new duo-narrowband filter. However, with 10-15 minute exposures, I get oval shaped stars. 5 minutes seems to be fine tho. I tried going with 15 minutes for some times, so I accumulated 7 images, and also 2 images with 10 minutes. These all have bad star shapes:
I still went ahead and stacked them alongside the clean 5 minute subs, and the end result is very good, against my expectation:
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For a comparison, I also did an integration with just the 5 minute subs, which is about half the exposure time, and with the long exposures also stacked, I dont see any negative effects on the stars in the comparison. Same size, just more signal in the nebula (obviously)
So, on first glance there doesn't seem to be any downside, yet my feeling tells me there should be some negatives coming with using worse data. Also regarding the saying "garbage in garbage out". I wonder at which point it is not recommended to use a frame anymore, as in how distorted stars have to be that it would really have an effect.
Can bad images make the entire integration worse, or will they just be ignored at some point?
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CS Tobi
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It will depend on how many bad frames you have overall, the algorithm will give images with better star shapes a higher "priority" so to say, but the signal of images with worse stars is still used. This means, with enough data you can keep satellite trails in and also a bit of bad data (more data is better rejection and noise). Clouds and such I wouldn't include, neither really really bad stars, but like you have it results in a good final image. So that's great I think, works as expected. 🙂
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edit: You can also opt to stack, say, 90% of frames, this will throw away data that is deemed worse.
