Hi all,
The IMX585 is very sensitive in the near infrared compared to most astrocameras and, interestingly, the RGB filters are comparable to mono from 850nm+
which matches almost exactly with a Sloan z filter (~ 825nm+) and should, in theory, turn an RGB into a mono camera at this frequency range.
I have an imx585 colour and I’m planning to do this experiment when my backorder for a Baader z-s filter arrives, and the skies allow.
I hope to be able to use a regular mono processing pipeline, but I also suspect that the actual transmissions will need a small “colour correction”, owing to the small region 825-850 where the channels have slightly different transmission rates (and they don’t track exactly perfectly either, blue is ever so slightly stronger than green).
Is there any way to apply a “colour correction” of this nature in Siril in this way, without debayering the image? Manual pixel math could work, if I know the bayer pattern… I’d even be happy manually creating / eyeballing the correction parameters.
I feel like I could write a little python script to do this, but I really want to keep everything inside of Siril! And, what a hack, this could be great for RGB folk to dip their toes into a full mono workflow!
NOTE: this is very specific to the imx585 sensor. This will not work for anything else that I’ve seen. Sloan z is very interesting as it has a lot of the Paschen Hydrogen lines (as well as the CaII triplet, some S and some O), but they are more likely to pass through dust. Arguably Sloan i is more interesting, but the rgb-mono hack doesn’t work there so it only works with the mono imx585.
… I’m guessing we’d need to find the correction factor and apply it to the subs, so that stacking would work correctly. And that does sound tricky.