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.
Hi all,
I like that APP makes it pretty simple to set a quality threshold for my subs; just by yanking the "lights to stack" slider back and forth I can not only set the proportion, but also see the exact frames being culled in the list. Bravo!
A question, though: the "quality score" is a bit of a black box to me. I see that SNR and FWHM scores are also available, but apparently not till after integration. What goes into the "quality score", and can I obtain the other two for my subs either "in the raw" or after calibration? And should I have been able to find this information on my own?
TIA!
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Here's an answer from Mabula I found on the forum;
The quality scores are relative. There is no absolute score to indicate what a good score is actually.
The score is calculated with a special formula that consists of star density, noise and star shape.
Simply said, star density and star shape are relative in terms of imaging scale in pixels. If you register frames of different image scales, this will become clear.
In relative terms, frames with stars with a large FWHM value in pixels will get a low score. But it does not mean that the frames are bad, it could simply mean that you are shooting with a very long focal lenght.
Thanks Vincent! I actually saw that response linked beneath my query as a related topic -- AFTER I posted it. I'll try to pay a little more attention next time.
It will take a little more thought to use the score, rather than some arbitrary FWHM, eccentricity number, or combination thereof. After all I don't care all that much about what percent I'm rejecting, I care about the quality of the frames. If I have a good, consistent night I might want 95% of them; a consistently bad night, perhaps 10%, and an inconsistent night maybe 50%. But perhaps I can suss that out by playing with the slider and seeing what frame-scores stay selected.
If there's an APP best practice for this, I'm all ears, as Ross Perot said.
Thanks again!
Thanks again!
You're welcome. 🙂 As for the best practice, it comes down to personal preference a bit I think and some experimentation. I usually never look at the frames anymore (blinking through them) as I know my rig is very stable now and things like aircraft trails aren't a big issue at my location. I tend to always go for about 95% to stack, with quality as the selected method and it always works very nice. If you, however, are in an area with loads of aircraft or other disturbances, it might be better to first do a pass through the frames before going this route. If a particular session makes you want to throw the slider down to 10%... I, personally, would just call it a day and go for the next. 😉 Satellite trails usually aren't a problem when you take enough subs.
Sigh. I could only dream of a "very stable" rig, I'm afraid. I'm culling frames due to eccentricity, or even jagged trails from time to time when there's some kind of hiccup. That sort of thing shows of nicely in lower-level stats, I'll have to throw some of my special brand of horror frames at APP and check out how it scores them.
Ow, sorry for that. Well those type of frames should be dealt with properly in APP using the quality method.
@rickwayne Where do you do this? Been using APP 4 years and dint know that was possible.
I believe they are discussing the "Lights to stack" slider in the Integrate tab.
Now if the slider were sensitive to how you've sorted the frames in the files pane (e.g., by eccentricity instead of quality for a specific dataset) that would be HUGELY useful. Have to see if it does indeed work that way. I've been sorting through the frames one by one and eliminating outliers manually, but the slider might be a nice, quick alternative. I'd probably still look at the dividing frame though.
