Hello chaps
As we approach nebula season I thought I would take a chance to have a discussion on the relative merits of scheduling RGB vs LRGB jobs.
It's an old argument, but what is not old is the technology and hardware we all have access to. I think there is certainly some CCD aftershocks still permeating through the astro community.
Modern CMOS cameras are so much more sensitive than CCD. AI deconvolution and noise reduction software are literal game changers (I'm looking at you, BlurXTerminator). BXT provides the biggest jump in image quality I have seen dollar for dollar and can really step up in not 'needing' a dedicated Lum stack.
So!
With these amazing new tools we have and the sensitive hardware, do we need dedicated Lum any more? Can we not just synthethise a Lum from the stacked RGB image? The synthetic lum can be processed as normal and be a *perfect match* for the RGB because that's where it came from.
L is a component of all R G B images anyway. This means we can put more imaging time in where it matters.
CMOS cameras are sensitve to different wavelengths, peaking in the red. So we need less Red than we need Blue. This means that using G2V star anaysis we can absolutely maximise the signal and colour balance of our image before we put it in to processing.
When we colour calibrate we are effectively asking the software to boost some and lower other colours. If we provide perfect R:G:B colour ratio raw files, or as near as possible, the software will have to 'do' less and more signal gets through.
The idea here is two fold: get more signal that isn't going to be dampened during colour calibration, and use less time for the same productivity on the pier. What is the point of doing 1:1:1 R:G:B when, for example, Pixinsight is going to boost the blue and dampen the red? The amount of imaging time that will be saved can be recycled for more relevant signal.
On a side note, narrowband imaging also requires ratios due to the massive abundance of Ha. 1 hour of Ha should be accompanied by much more O3 and S2 due to their rarified nature. This is more of an art, I think, but rarified O3 and S2 need some serious love :)
I've asked Robin Glover (of Sharp Cap) for his views on this and will post here if I get a response.
Perhaps we could do a short test?
An example of RGB only:
https://www.astrobin.com/xvxxym/
Cheers
Pete