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.
I am seeing sets of nearly parallel, but not horizontal, bands in images that have been integrated and processed by APP. I do not see this in the raw light images.
In the example image, zooming into the left-of-central region of the image reveals aprroximately horizontal bands, but these bands are "wiggly," as opposed to perfect mathematical parallel lines. On the other hand, zooming into the central right portion of the image reveals similar bands, but in this case the lines run roughly from upper left to lower right.
This image was processed after integration using the "remove light pollution" and "calibrate star colors" tools in APP.
Any ideas what is causing these artifacts and how I can avoid them?
Jean
Making a followup post because I see this string is marked as being "solved." But it isn.t
To me this looks more like a lot of noise and possible issues with data calibration. The saturation is also very high it seems, so that amplifies any noise/issues. How is your data processing workflow, can you describe that?
I pretty much just work through the steps in APP using the defaults. Once the image is integrated, I repeatedly use the "remove light pollution" tool until the image becomes as clear as possible. I then do one application of the "calibrate star colors" tool. I then save the image in TIFF format for processing in Paint Shop Pro. In that software I primarily use Levels and Curves to improve the image, although I will also use some of the noise reduction tools.
I should mention that the banding seen in the example image appears usually for relatively faint onjects. I do not see banding in brighter images.
That you see it in fainter objects points to it being in the brighter images as well, but there you don't stretch as much so the background stays below a limit for you to see. Do you also see these when you just look at what APP produces, so before any other post processing? Do you dither when shooting and are you using all calibration files?
@vincent-mod
When I use only the "Remove Light Pollution" tool, the same kinds of banding appears as in the final fully processed image that I posted here. The banding does not seem to be present in the integrated image prior to using that particular tool.
I do use all the calibration files.
I have not done any dithering up to now. I use PHD2 for guiding and SharpCap for image acquisition. PHD2 does have dithering capability, but it seems it is manually applied, which I would not want to do. SharpCap also appears to have dithering capability, and it appears to be automated, but I am not sure if it is available in the free version, which is what I have been using up till now.
Do you have any suggestions regarding automated dithering software?
Dear Jean @jpiquette,
I have read the whole topic and I see the banding in your image. To me, this really looks like a data calibration issue somehow, or perhaps a problem with your camera electronics (like electromagnetic interference).
What kind of camera do you use and how do individual darks look like? Is the pattern visisble in single darks? Is the pattern the same in different darks? If you do not see it in your darks, please make some darks with really long exposure time, like 10 or 15 minutes and check if the problem shows then 😉
If it is a question of data calibration, then big dither steps would help countering the problem, but is it not the solution, the solution would be to get a better handle on the actual data calibration process.
If it is a question of a problem with the camera electronics, the banding patterns will show in the darks and they will be different in separate dark frames, then you have a clear indication of a hardware problem with the camera or the camera connector cable.
Mabula
