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.
Based on what this article describes (the theoretical part seems sound),
https://siril.org/tutorials/synthetic-biases/
could the option to add a value (in ADU) instead of bias (or masterbias) to avoid adding noise to the image be included in APP?
Thanks for your attention.
Hi @anofeles,
The method as offered and discussed can be used for sure.
But... a perfectly flat bias or darkflat to calibrate flat frames (or lights) by using only an offset instead of real sensor data is something which I would only contemplate if it were impossible to create proper bias, darks or darkflats. And this is not a very difficult task I think, so why would you want to go down that route?
I would advice to simply shoot enough bias/dark/darkflats and you will get proper data calibration on pixel AND larger than 1 pixel scale (there are definite sensor noise patterns in clusters on these new CMOS sensors). The static offset simply can't offer that so it will be less good, especially on sensors that are getting of age where even the bias signal can be quite different across the whole sensor. You would be surprised what bias signal an old cmos or ccd camera can give when compared to the signal that the sensor gave when it was brand new!
In my opinion, the static offset method is just a lazy person's way to accomplish something with less precision and definitely more error-prone when compared to proper data calibration where the current state of the camera is always included, so it is a bit difficult to advice this to users even. I would not.
But..., we will try to add it as an option though at some point. It is on our ToDo list.
Mabula
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Thanks for taking this into account.
Yes, obviously, biasing is not very time consuming (especially compared to darks or flats). It's not because of the time that can be invested in their creation but because of the noise they can introduce in the image. It would only be within the reach of the most modern CMOS sensors, of course, but it would be a way to try to avoid it.
Taken from siril's website:
"Taking a bias image must be done at the fastest possible speed, to avoid adding signal and thermal noise that would interfere with the processing. However, a bias will contain, in addition to its offset level, a certain level of noise. This is why we advise you to take as many biases as possible in order to minimize the noise in the final master. Remember that when you subtract two images, their respective noise is added. Therefore, using 20 biases introduces more noise into the final image than using 200 biases".
As said, thanks, Mabula, for taking it into consideration.
Best regards...
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