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.
First off I love the ability to do this extraction. However, it would be nice if that can be selected as a filter, and than it actually uses that information to do the extraction for both of them. Currently the workflow to do the extraction is a bit cumbersome as you have too do 2 extractions, than you need to combine them. I would love to see this workflow get some much needed love as it is a fantastic feature.
@romonaga Thanks for your comments, Robert. Improving the Ha/OIII extraction is on the TODO list. I am not sure if it will be part of APP 2.0.0 and if it isn't then it will be for a release soon after that one.
Wouter
I have a question regarding that. i usually do the Ha-OIII Color extraction. How is the third (blue) channel composed? I use that so I can do a fake SHO palette.
But as I understand, it’s better to extract them and then do the combination?
How do I get the third channel?
It is cumbersome to extract Ha and then OIII and then Ha-OIII to get the the blue channel.
I’ve seen videos that extract the mono channel and make that the third channel. Which would be the best route to choose?
The easiest is the way I do it now, Ha-OIII color -> Split channel -> RGB Combine
/Stefan
@digitaliz-se Both the Ha and OIII channels are mono channels. To create a color image, you can use the HOO formula in the Combine RGB Tool. That means that Ha will be used for the Red and OIII for both the Green and Blue channels. There are ways to create a synthetic third channel and using that for Red, while using Ha for Green and OIII for Blue to create a fake SHO image. APP doesn't have a specific way for doing that but you can search on internet and then apply accordingly.
HTH, Wouter
