May 27 2026 APP 2.0.0-beta45 has been released !
Fully Multi-Threaded LNC, many improvements for the registration engine, platform upgrade, and further tuning of internal memory consumption and memory release back to OS.
Apr 14 2026: Google Pay, Apple Pay & WeChat Pay added as payment options
Update on the 2.0.0 release & the full manual
We are getting close to the 2.0.0 stable release and the full manual. The manual will soon become available on the website and also in PDF format. Both versions will be identical and once released, will start to follow the APP release cycle and thus will stay up-to-date to the latest APP version.
Once 2.0.0 is released, the price for APP will increase. Owner's license holders will not need to pay an upgrade fee to use 2.0.0, neither do Renter's license holders.
Hi,
I'm new to APP. I recently was able to get a large portion of a clear night with which to accumulate subs. I ended up with about 400 subs. I analyzed the subs and the normalized results fell in the .5 to >.9 range. I decided for best quality to only use anything that was above .7 normalized results. However I could not find a simple way to cull in bulk. when I sort the files quality I see the plot sort as well but the quality score and normalized score are different so its hard to tell which light frames I want to set as limits in the file list. Also I noticed I can delete the frames or just choose not to integrate the frames but is it possible to mark the frames as "bad" or something like that so I can easily tell what I used and what was not used and I don't have to delete the subs right away. Thank you.
Eli
Eli
The short answer is to just decide roughly how many subs you want to exclude and set the "lights to stack" slider in the "6) Integrate" tab to an appropriate percentage. So if you have 400 subs and want to exclude 100 just set the slider to about 75%. With 400 subs there's no reason to be too precise. I know this isn't exactly the question you asked, but its an easy solution.
The more general question is when and why should subs be excluded. Certainly if you have subs that are wind affected or have tracking problems or are clouded out these should be deleted, but if the issues are minor (varying background, minor cloud, etc) there is an argument that you shouldn't throw away data. I should note that not everyone agrees with this argument. Also - remember that the quality measure is relative not absolute - sometimes .5 is good enough.
Finally, if you have doubts - experiment. Stack 100% of subs then set the slider to say 80% and stack again. Go and watch some videos, then come back and compare the two integrations - see which one you like best.
JC
These are the steps I follow when culling in APP, analyzing one graph at a time:
- Sort by star shape – Remove the subs with distorted or irregular stars.
- Sort by star size – Remove any outliers again.
- Sort by S/N ratio – Watch for peaks, as they often indicate issues like clouds or obstructions (e.g., buildings). Remove those.
- Sort by background level – Cull again if needed, but even the worst subs usually still add value to the final image.
- Recheck all the parameters mentioned above.
- Sort by overall quality – Remove any subframes that clearly stand out as worse than the rest.
/Stefan
Thank you John and Stefan,
That was very helpful -it's basically what I do but it's reassuring that others are doing it the same way. Its just that unless I delete the files I don't stack there's no way I can easily tell what sub were stacked and what weren't. If I do multisession I keep culling the same files unless I deleted the files I haven't stacked. I suppose I can use the masters of stacked subs but there are times that I'd like to redo the integration. Anyway just a small annoyance I hope gets noticed.
Thanks again,
Eli
