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.
OK, here's the problem: for some reason Stellarmate won't play nice with my mount so I'm confined to 45 second subs. A few nights ago I took about 200 45 sec subs at ISO800 with my full spectrum modded Pentax K-5 DSLR and a 300/4 lens at the half stop between F/4 and f/5.6 in my Bortle 4 backyard. I see some stars and I know that the horsehead and flame should be in the frame (a quick capture at ISO 3200 showed them quite clearly). When I stack the subs (and bias frames, no darks or flats), I get the serious data warning, but go ahead anyway. The final stack at 16.306 seconds exposure, shows nothing. Even when stretched to the max, there's no nebulosity, just some stars.Â
What could cause this and how would I be able to deal with this (other than trying to get Stellarmate up and running to enable autoguiding)?
Many thanks in advance!
Hans
Dear Hans,
Do I understand correctly that you are only using lights and bias frames? In that case the warning indicates that either
- your bias are not compatible with your lights in terms of sensor gain and or offset
- your lights are simply exposed to shortly
- Or the bias are not in fact bias but something else... how do the bias frames look?
It definitely sounds like the bias subtraction subtracts much more than only the bias signal, so maybe you even have a light leak in your optical train?
Mabula
Dear mabula.
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Yes, I have shot only lights and bias and in the meantime I've shot flats as well. The sensor gain for all of them is ISO800 and I can share a bias frame tomorrow when I have access to my data again. I guess this may be down to the lights not being exposed long enough, but that makes me wonder how I can determine whether there's enough signal in them? Is there a metric for this?
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I don't think there's a light leak as the lens and camera a covered during the imaging, as is the viewfinder. Is there a way to identify light leakages (perhaps stretching a dark to the extreme?)
I'm about to process a dataset taken with a different DLSR and if that doesn't have the same problem/warning, I'll share that as well.
Many thanks,
hans
It would be the easiest if we can have a look at some of the data indeed. You can upload 10 lights, 10 bias and 10 flats (if you have those) that display the issue to our server.
Hi Vincent,
Apologies for taking so long, but things hot swamped a bit in my inbox. Anyway, I've uploaded the lights and bias frames. No flats for this session, I'm afraid. Many thanks in advance!
All the best,
hans
Thank you Hans! Unfortunately I'll be in London tomorrow morning so I will have to look at the data in a week, apologies for the delay as well.
No worries at all! Enjoy London and I'm busy as it is processing my comet data.
Hope to see your comet on the Pentax forum, Hans!
I'll certainly share it as soon as I have wrestled through Photoshop....
