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 always go through all images visually to delete obvious bad subs. Then Star shapes and delete outliers and the same with star size. After that, I check signal/noise ratio. If you have couple of subs that has strong s/n ratio and the rest is like 70%, them I delete those since they are due clouds or other streaks of light thar shouldnt be there. After that I check background, I delete obvious subs shot during twilight,. Sometimes I keep them, but the obvious are deleted. Lastly at the least important is the quality check. After that I stack 100% of the subs.
If you leave the integrate box set to automatic then APP will weight the frames using its own quality measure. Low quality frames will receive a lower weighting. In many cases - pehaps most cases - this means you don't have to worry about some frames being a bit sub-optimal, and you can stack 100% unless you have reason to think some frames are particularly bad. I often rely on this, but if I suspect some frames are affected by clouds I may look for them and delete them, or I might reduce the lights to stack to 80% or so.
You can put a fair bit of effort into identifying sub-optimal frames, but often this will not necessarily improve your final image unless there are some really horrible frames.
@connor231 Just noticed I have always had mine on automatic (quality is greyed out) but when I started getting star registration failed I started using best 90% 75% or less.
Registration failure indicates there may be something seriously wrong with some frames. In this situation you should identify the problem frames and probably delete them. Stefan has given some good advice above on how to do this, although these days I mostly rely on the analytical graph (at least to start). I usually run the graph after 5)Normalize, but if registration fails it can be run after 3)Analyse Stars.
Typically registration fails because of clouds or tracking problems but there are other possibilties.
On the face of it you have two separate problems - a registation problem and a calibration problem. I guess it might be possible that the registration problem is caused by the calibration problem (although that seems unlikely to me). It would be easy to test - just run APP on your lights, with no flats, no darks, no darkflats, no BPM. If the frames register you can just move on to the calibration issue. Issues with calibration frames are important and need to be addressed.
Its difficult to problem shoot without detailed knowledge of your equipment and workflows, but these are the basics (forgive me if you already know all this):
gain and offset must match between lights, flats, darkflats and darks
exposure time of darks (and ideally temperature) must match the lights
exposure time of flats must match darkflats
exposure time of flats should be long enough to achieve roughly 50% illumination (check histogram - be careful about believing the histogram of dslrs)
exposure time of flats should be long enough to avoid non-linear behaviour of some sensors (at least 2 seconds is a good time to aim for)
light source for flats must be even and clean - I've always avoided twilight sky flats, although they used to be used a lot
no light leaks in the darks or darkflats
Even knowing all this it is still possible to just make a mistake. I've certainly done that - human error -happens all the time. 😉Â
If your optical train has not been altered these frames could all be taken again after the event.
That is not an error, but an important warning message, it warns you about a problem with your data calibration workflow. It means that the masterflat will be created without subtracting bias or dark flats from the flats. So you really want to fix that as well. When you loaded your flats, did you load compatible bias or dark flats so a masterDarkFlat or MasterBias is created that can be subtracted from the flats?
Stefan and John, thank you very much for helping Trevor here.
Trevor, I can confirm the advice from both Stefan and John. And try to fix that calibration warning first. It should not show when the masterflat is created. Sometimes this issue happens because the flats have a different filter tag in the fits header then the bias or dark flats. So double check that the filter is assigned correctly in the frame list after having loaded all data and before starting the 2) Calibration.
You can also disable the multi-filter/channel processing to see if that removes the calibration warning. Then you know for sure that the warning is caused by a wrong filter assigned between the flats and the other calibration data.
