So I was really excited to try the Extract_HA_OIII script until I found out the resolution is only 1/4 of the original. Instead of 6224x4168px I get 3112x2084px. That’s quite a big drop in resolution 26mp vs 6.4mp. I can’t accept such a big drop in resolution. Any reason for this?
Hello, using a sensor that has one pixel on four that is red doesn’t make this easy. If you can’t accept it you can use a monochrome camera with a H-Alpha sensor of course. Using a dual band filter in front of a color camera is the easy solution, but it has drawbacks.
There is an option in the command to upscale the Ha image, it will have the same resolution but the original definition, if you can accept this. See Extraction — Siril 1.2.0 documentation
Thanks. I will just split the rgb channels and recombine in HOO or SHO.
You will have more noise. Especially in Ha.
In this case you are working with interpolated information from the de-bayer.
The HaOIII scripts use the CFA (which is 1/4 of the sensor are) but upscale with
drizzle. So if you have a well dithered stack, this might be the preferred solution as
you will have the same image size in the end.
I always stack my dual band OSC imaged with ExtractHaOIII as it provides more
control and is much faster.
Especially my OIII signal sometimes needs more care when stacking, so I stack the
created sequence with different parameters.