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 Wouter, would then be calculated with a minus as a sign / 10 to the power of 3?
@minusman Sorry, I forgot to mention that. 10 to the power of -3 = 0.001 or 1/1000.
Thank you very much Wouter, Now I can start with the numbers. Because when normalizing a stack, scientific notation comes up too. Unfortunately I couldn't do much with it, but now I know.
Dear Mabula, @mabula-admin
thank you very much for your time and the thorough analysis. I can reproduce the histograms you describe above and get what you believe causes the problem. I have checked every single frame from the lights, darks, bias and flats and they all have the Offset of 30 you mention. The ASIAir does not even offer an option to modify the offset - it seams to be built in. The only parameter that one can change are the temperature and the gain settings.
Next, I rebuilt all master files having verified that the Offset is 30 on all input files - and the resulting master file show values in the "high" 1920 range you show above. This is also the case with all other master-files from other imaging sessions. Maybe that's okay after all?
Do you have any other idea what causes this problem?
Thanks for pondering about this,
Phillip
Hello Philipp, you can upload 5 pieces of each calibration image (DARK, darkflat or bias & flat). No master files. There you can better judge what is going on with the files.
@rudibarani Actually that was going to be my next suggestion. Can you do that and let us know as soon as the data are there? Please use the same directory as before. Thanks!
Dear Wouter, @wvreeven
thanks for the chance to upload additional data to help solve my problem.Â
I have uploaded darks, bias and flats - 5 files each.Â
Flats were created using the Lacerta Flatfield Box and the auto-exposure function of the ASIAir.Â
If you need additional data / information, please let me know.
Best,
Phillip
Hello Phillip, when I look at the statistics of the data I see that the exposure time for this filter is still much too short. The Mean ADU value is only slightly above that of the darkframe despite the 300s. This is also visually visible by the stripes in the lights. I have the same camera and always expose so that the stripes in the lights almost disappear. But this does not explain the bad darkframe calibration. I can only assume, maybe a USB connection problem.
