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 have some very bad flats from a remote telescope. They have numerous dark rings in them, I assume this is dew? I only realized this when I processed the lights to completion. Regardless, the defective flats is not my puzzle, it's what I see in APP that baffles me.
I had 6 lights of each of LRGB. The first fully processed light (CA, STAR, REG, NORM) of each channel is always clear of the ring defects. Only lights 2 thru 6 show the rings. Why is the first free of defect? It almost appears that the flat correction was not applied to the first. the Have I discovered some bug in APP 1.083.3?
Attached is a PNG from one of the defective lights. I don't see those circles in the first image of each channel.
These rings are dust on the sensor. They indeed require proper flats to be removed. Personally I've seen quite a few issues with online telescope services and calibration files, so that doesn't surprise me. It appears very hard to manage that properly, remotely. So, if you have these in your result, that means either that the flats are not applied to the lights, which can be due to a mismatch of calibration data vs lights. Or the flats themselves are not ok, not calibrated well, etc.
I would need to see what you used to be able to judge this better, so if you want to upload the data (the ones that fail), including the calibration data (masters are fine for now), that would be great.
I created the upload folder as you suggested. In it are 4 files: (2) of original red light images, (1) Red MF generated by APP, and (1) Red "integrated" file.
The integrated file (isn't that the same as "stacked"?) actually doesn't look too bad, but the dust rings are obvious.
The master flats are full of dust rings. Should such flats be able to remove dust rings from the lights?
And why is it that the first fully processed light, pre-stack (CA, STAR, REG, NORM) appears to be free of dust rings, but all others are not?
Difficult to judge based in this data alone. But I am seeing a lot of dust on the masterflat you provided, so with that much it can become tricky for software to perfectly correct it. Also, there seems to be a lot of vignetting, I wonder if a flat that has been exposed longer would make better flats as well.
