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.
Should I manually remove light frames that have cloud coverage prior to running an APP session?
And if so, how aggressively? If a few wisps of clouds are visible, should I include or remove those lights?
And how about airplanes? Does it make sense to remove those frames, too?
@tbarn Tom, obviously clouds negatively influence the integration result so it is much better to use as few frames with clouds as possible. The same applies to airplanes, meteors, satellites and other transient phenomenons. Having said that, it is also clear that not all of us have the luxury to keep on shooting and shooting images until all are perfect.
Regarding clouds, APP analyzes each frame and assigns a quality score to them depending on the shape of the stars and the signal to noise ratio of the stars with the background. Based on the quality scores, it applies more or less of the frames to the final image. If the star shapes are good but the SNR low then it may still decide to use the star data for more intense star colors for example. On top of that, in tab 6 you can select if APP should stack all images or a percentage smaller than 100 of them. It is up to you to select what percentage to stack.
Regarding airplanes, meteors, satellites and other transient phenomenons, APP determines in each frame what signal corresponds to that found in other frames and uses a technology called sigma clipping to get rid of transient phenomenons. Here, the more frames you have, the better because that way APP can much better build up statistics of the frames and decide what to include and what not. If you see that APP didn't get rid of all airplane signal then you can play with the outlier rejection parameters in tab 6.
@tbarn Adding to this, after APP has performed step 5, Normalize, you can sort the frames by sky background and create an analytical chart of the sky background. You can then easily identify the frames with clouds and discart those.Â
