Stacking in APP + Color Calibration in PI SPCC leads to green cast - any help?

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Christian Koll avatar
Hello!

I used to stack my images in Astro Pixel Processor (APP) and then color-calibrate (SPCC) and deconvolve them (BlurXterminator) in Pixinsight.
Why stacking in APP? - Because I am used to it from before acquiring PI and I found it was much faster and more convenient that stacking in PI.

However, I found that the color calibration with SPCC did not produce propper results - I always get a greenish cast, especially noticeable in galaxy photos.

Referring to the SPCC manual, I figured out that this has something to do with the de-mosaicing algoritm for OSC-data (which is the case).
According to the manual, you should drizzle OSC-data (scale 1) and not use the VNG-debayer method. This works well when staking the data in PI (WBPP) and I get the correct colors after applying SPCC.

However, neither using the Bayer/Xtrans-debayering, nor a drizzle integration will fix this in APP.

The easiest solution will be stacking entirely in PI from now on, of course.

However, I have some old data where I only kept the APP-masters of the bias and flat frames - these are unuseable in PI.
So, restacking them in PI is not possible, unfortunately (I also don't have that OSC camera any more).

So if anybody has had the same issue and found a solution / setting in APP, please let me know, thanks!

Chris
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andrea tasselli avatar
You can always color calibrate in PI, just don't use SPCC (waste of effort if you ask me). To get started use only CC and see what happens. I never had any issue with color cast using the VNG algorithm, by the way.
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