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'm processing a new batch of images today and noticed that the neutralize background box is unchecking itself after I begin normalization. I haven't noticed this before. What causes this?
Then I get the "critical warning: background neutralization turned off" window at the end of the normalization process. But I checked the box before I started normalization.
@safinsd Hi Susan, what version of APP are you using? And can you tell us something about the data you're processing?
Thanks, Wouter
@wvreeven Hi there. It's version 1.083.4. I'm stacking FITS lights and darks. This didn't happen on my previous stack using lights and darks from the same telescope.
@wvreeven I'm doing another stack now with different but similar data from the same telescope and the neutralize background box didn't uncheck itself. Using same APP settings.
Only appreciable difference with this stack is a lot less subs.
@safinsd Intriguing. Are all the lights from the same imaging session or are multiple sessions involved? If the latter, does the button stay enabled when using lights from a single imaging session or also when mixing lights from multiple imaging sessions?
Did you select the smaller sample randomly or is there a certain coherence between the lights?
EDIT: do you only use mono lights or OSC light or do you mix those? If the latter, does the smaller set have mixed lights as well?
I'm processing a new batch of images today and noticed that the neutralize background box is unchecking itself after I begin normalization. I haven't noticed this before. What causes this?
Hi Susan @safinsd & @wvreeven,
Background Neutralization can be turned by APP of if any of the frames are under-exposed after data calibration. So it happens because 1 or more of the frames that you loaded clip to much to the black point / zero value after data calibration (or no calibration if no calibration data was loaded.) The general console does warn you about this when it happens.
Background neutralization can only work well if the RGB values of the background sky as found by APP are positive. In your case, some frames have real negative sky background values and thus Background Neutralization is turned off as a precautionary measure.
This is no problem and actually very important. You can still get a good sky background if you run the Calibrate Background tool on your integration (or the Remove Light Pollution Tool which will do Background Calibration automatically).
Mabula
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Then I get the "critical warning: background neutralization turned off" window at the end of the normalization process. But I checked the box before I started normalization.
Yes, so APP warns you that it is turned by APP because your data does not allow background neutralization to work properly 😉
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I do get light leak warnings sometimes when the background of some frames is significantly lighter than the rest.
@safinsd Intriguing. Are all the lights from the same imaging session or are multiple sessions involved? If the latter, does the button stay enabled when using lights from a single imaging session or also when mixing lights from multiple imaging sessions?
Did you select the smaller sample randomly or is there a certain coherence between the lights?
EDIT: do you only use mono lights or OSC light or do you mix those? If the latter, does the smaller set have mixed lights as well?
They were from the same session. The smaller session was from another night, so the only correlation is using the same telescope. These are all OSC. The button hasn't unchecked itself in any subsequent stack of other observations. Assuming it was a data issue.
