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.
Hello,
I'm struggling to understand why the satellite rejection doesn't work properly when I apply a x2 drizzle (droplet: 0.5, scale: 2.0) whereas in classic interpolation mode with the same rejection parameters it works perfectly.
And this applies regardless of the type of integration (average, auto).
The stack is 53 images of 300s each
Francis
You haven't said how many dithers you have done, but even if you dithered every frame then a 2x drizzle with droplet size 0.5 is a lot to expect from only 53 dithers. I don't usually push droplet size below 0.8, and I like to have at least 60-80 frames/dithers. I suspect with such a low droplet size you are just not getting enough data in each pixel for good rejection.
JC
@connor231 Thank you very much, John, for your reply.
I only have a rough idea of how drizzle works. I set this droplet value based on the help pop-up for the scale parameter.
I usually do dithering every two images. That gives me about 26 dithers over the entire sequence.
I'm going to continue my tests by playing with the droplet parameters, starting from 0.8.
Your welcome Francis
I'm no drizzle expert either, but once you've had a few failures and a few successes you get a feel for what it can and can't do. But remember it is a noise injector and needs lots of frames/dithers - the more the better.
For a normal (non-bayer) drizzle with a mono camera my starting point is drop size 0.8 and scale 1.5. Often that's where I end up as well. It does depend on whether your aim is to get a larger image or fix up 'blocky' stars.
If you are planning on using drizzle you should probably dither every frame, unless your mount can't handle it or unless you plan on hundreds of frames.
To be honest - I'm still trying to get my head around best practice for Bayer drizzle. But I only use a OSC camera for widefield, so I'm usually only drizzling to get rounder stars - so I can afford to use conservative settings.
JC
