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.
Hi,
Having sorted out why my edited stacks were looking odd in Photoshop I'm now on to the next questions! In the tools tab on the left side of the interface, a number of the tools have a requirement to draw rectangular boxes on the image and then calculate a result. Is there any particular preferred method for this? For example I saw a youtube video where a chap recommended a number of small boxes across the image missing as many stars as possible for background calibration. I have no idea if this is what i should be aiming to do though or not! The ones I can think of so far are:
Vignetting correction
Background calibration
Remove light pollution
Basically what should I be aiming to do for each when drawing the boxes!
Cheers
Ed
You don't have to draw boxes outside of stars, APP is smart enough to see what a star is and what background. I usually stretch the preview a lot (30%, with the preset box on the right of the screen) and up color saturation a lot. This shows me which areas seem true background and what the problem parts in the image are. I then draw just 4 or 5 rather big boxes around the image and press "calculate". Then I check the result and based on that either create new boxes or I add a few, it's not needed to draw a lot of boxes. Gradients should be gradual across the image, not all over the place.
Thanks Vincent, so do you draw the boxes only in the problem areas? I'm trying to understand where I should do them, in the problem areas, in the ok areas (so APP can take these as 'what the background should be like') or across an area which encompasses both so a gradient is captured in a box.
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Thanks
Ed
You should avoid drawing them on the area's with nebulosity, that's why I overstretch to make that more visible. You can just place a few all over (start with 4-5, doesn't really matter what it looks like, as long as it is background), check the result and the possibly place a few more. APP will built a model of the gradients (you can see that model by clicking on "show corrected image", that should show some gradual gradients and if it then looks good to your eye, it's likely fine already. When background consists of other light pollution, it becomes more tricky and you may have to go back and forth a bit with placing boxes and checking the results.
