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.
For some of my captures, star tracking fails occasionally (typically when the tracking star is too faint, or there is some wind) resulting in some overall drift over time. Most of my frames are still good, I just reject the ones where stars are elongated or have other artefacts.
Because of the drift, when I stack the result, I don't have the same number of stacked frames at every pixel.
Now I'm in a site with some light pollution, and so in positions in the final stacked image where I have many frames, the background looks very light and obvious. Were I have fewer frames, it is darker. The attached stacked image shows what I mean. The result is disappointing because it lack color and contrast.
This effect is very difficult to deal with on the stacked result. Is there a way to correct the background on every frame so it is darker, so when I combine all the frames, it stays dark everywhere ? In other words I would like to estimate the background light pollution pedestal on every frame and subtract it on each of these frames, so when I combine all the stacked images, it is not as bothering. Is there a way to do this in APP ?
On the attached image, see how the background is much darker near the top of the image than near the middle? this is not due to the C12 galaxy presence, but due to the light pollution background.
Thanks.
It does look like the background is black there, which would be too dark I assume? 🙂 Did you use some Light Pollution Correction to see if that would help (it only does properly when you do have data of course)?
