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.
In the past, I've read that it is ill-advised to mix, for example, 60s luminance with 120s luminance in the same stack. Is that still true? Perhaps I misunderstood the context. What if I assigned 60s luminance to Session 1, and 120s luminance to Session 2. Followed by assigning both stacks to the luminance channel using Color Combine. Is that a recommended solution? I'd hate to have to choose between 60s or 120s. I'd like to use both, if possible.
Thanks!
Mine are OSC images, but I do the same with exposure lengths and with gains, for dynamic range. I used to really, with a 12 bit camera, but stick to single settings for my 16bit one. You should be OK for dynamic range or tonal range integrating as sessions (singly or as separate integrations from one process in the integration tab). So long as you assign your calibration frames (if you use them) to the right sub exposures, it should be OK.
My most-recent image mixed 15", 30", 200", and 600" exposures. Whether it was inadvisable I couldn't say, but it came out pretty ok. APP integrates the various exposures pretty well; I have had less success with mosaicking images that differ wildly in exposure, but APP will handle that too if you have enough patience to sit through the LNC iterations.
It's fine to mix, but it isn't super beneficial yet. What you're probably after then is a HDR integration and APP doesn't support that yet (it's on the list of things to add though).
Thank you, everyone.
I want to take every opportunity to increase the total integration time of a faint object. I've been given several hours of additional luminance frames by a generous person, but the exposure is different and the optics are slightly different as well. I have watched the video tutorials on this topic.
So, I have a good follow-up question: "If adding different luminance frames captured by the same equipment is not very beneficial, then what is the benefit of a multi-person project?" The question is silly, but why is it beneficial in one context but not another? Or am I reading too much into the reply? Clearly, there are various degrees of "beneficial".
Thanks again.
Ok, so to be clear... more data = good. 🙂 The more data you have, the lower the overall noise and the better the signal. Of course you wouldn't want to combine very bad data with good data preferably. But if you combine a lot of nice data, even from different scopes, that will be really nice as an end result for sure. The thing with different exposures is that you usually want to use that to get more detail in over-exposed stars and galaxy centers etc. That specifically is not yet a feature really.
More data is generally better, especially if it is good data. APP doesn't have a dedicated HDR exposure mixing, but its not so important since lower exposures (maybe your case) might have better star color balance (sometimes is the case for OSC cameras). Anyway, it will help SNR assuming there are no major sky background differences and improve rejection algorithms for the background levels.
You could try one curiosity test to see for yourself. Integrated 50 exposures at the longest length, then 50 with the shortest length (or whatever number you have, but ideally more than 20 subs). Then add half and half of each up to the same number of subs and compare the outputs in a similar region at high magnification non the viewer to satisfy your self you are not worsening anything. Then the integration with everything together should in principle be the best scenario for the data assuming no massive deviations in the data sets aside from exposure.
Thank you, Colm. That is great advice!
