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 recently bought an owner's license and I'm trying to get back to speed. Previously, I used APP for a couple of years on a rental basis; at that time I used it mainly for nighttime sky shots with a Nikon DSLR and, usually, a 50mm or 35mm prime lens.  For the most part, I've used only light frames and gotten good results that way. However, occasionally the output image will have lots of hot pixels among the stars, and I'm not sure what causes that to happen because it seems to be so random.
On a recent occasion when this happened, I added in bias frames and redid the stack, and that completely solved the problem.  But when I tried it again on a different set of exposures, it didn't work.  Is there something up front that I'm doing wrong? For example, am I choosing too high a star count? Â
Sequator, which is probably the best free tool out there, has an option to "merge 4 pixels", and this seems to prevent hot pixels. So naturally I wonder if there's a similar option for APP that I should be using up front.
Best thing to tackle hot pixels is calibrating your lights. Period.
Darks do the best job for me. Bias can help a bit, but will only show hot pixels at higher temperatures (if you are using dslr). As hot pixels always show with higher temperature (long exposure and/or hot weather). Maybe thats why it sometimes doesnt help.
And app offers calibrating with a bad pixel map, use atleast this if you dont want to calibrate with dark frames. If you got a good one you can use this for a couple of month...
You can dither your lights to get hot pixels removed due to outlier rejection. (But if you dont guide or have perfect alignment, that shouldnt be a big issue)
After calibrating my light frames, do I delete the light frames I loaded originally? Â
Do I add in the calibrated lights I just made, or does that happen automatically?
Apologies if these are elementary questions, but with so many files involved in the process, it's not entirely easy to tell by looking at the APP UI.
You can just load your lights and calibration data and then go to tab 6 and press the integrate button, this will go through all steps with standard settings and unless you're doing something special, this should work fine.
You can just load your lights and calibration data and then go to tab 6 and press the integrate button, this will go through all steps with standard settings and unless you're doing something special, this should work fine.
When calibrating the lights, can I usually just take the defaults (i.e., the automatic settings)?  FTR I'm using just a DSLR and usually either a 35mm or 50mm f/1.8 lens, which I usually set to around f/2.2 or f/2.5.
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Yes that is usually fine. Obviously, if it doesn't work out you may have to change a few settings, but with regular and good data this is usually not required.
