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
Can I create a color image only for O3 with APP?
I photographed the squid star cloud, and it is well shown in monochrome images.
LRGBHOO synthesis does not have the color of the squid star cloud.
So I want to see the color image of O3 alone.
May the night be sunny
@mo-mo If you only use the OIII channel then the data by definition is mono. The pass band of the OIII filter is so small that is effectively eliminates any color information. In order to get a color image you need to at least combine OIII with an Ha (or R) image.
The lack of color in the LRGBHOO image may be due to the contribution of L. Adding that generally tends to wash out colors. Do you get colors if you create an RGBHOO image instead? If it does then we can help you add L as well while maintaining color.
HTH, Wouter
Thanks for the answer.
I tried RGBHOO.
Compared to LRGBHOO, the color of O3 is better, certainly.
And then I realized that I had encountered a new challenge. In other words, the entire image is biased toward bluish-green because the color of O3 is strong in all regions.
I think this is correct in principle, but I don't know how to emphasize only the squid nebula. It would be nice if the APP had a function for this.
thanks in advance
@mo-mo I am not sure what you mean with "emphasize" but if you mean "use a mask" then this is not possible (yet, I think) in APP. If you upload your L, R, G, B, Ha and OIII images then we can try and help you get the most out of it. Without any example it is hard to give you advice.
Wouter
hello
I uploaded six files to the folder.
I would be very grateful if you could give me some advice.
Thank you
@mo-mo Thanks for uploading the images.
The signal of the Bat Nebula in L is very low and the Squid is completely absent, which is why the colors become very pale when you use it. The signal of the Bat Nebula and particularly the Squid are very low in R, G and B, which is why they don't become very visible when combining all RGBHaOIII images. So you probably get the best result by
- Combining the R, G and B images into an RGB image.
- Combining the Ha and OIII images into an HOO image.
- Reducing the size of the stars in the HOO image.
- Combine the RGB and HOO images such that the star colors of the RGB image and the nebulae of the HOO image are used.
There are several posts on this forum that explain how to do that.
Wouter
