Color Calibration

[multiweb]

Hi guys, I have a QHY8 camera. I've read posts on this forums about color balance and how we know we have the right colors in our DSO when doing RGB composite. I also heard about shooting a white and grey card in broad daylight to calibrate the camera colors. How does this work? :shrug: What am I looking for in the shot? I don't understand the concept. Any help/tips would be much appreciated. Thanks heaps.

[Gama]

You dont know what the exact colours are of DSO's. Every persons processing and exposures dictate the final colour image.

I just adjust the colour balance until it looks like it should. Others may use tools or specific tests to get closer, so maybe someone else may comment.

Theo

[multiweb]

Hi Theo, that's what I'm trying to avoid. Because when you think about it, every DSO is going to end up with a different color calibration if it's based on a "pleasing" colour. I'm trying to work out a consistent base to start from. I heard people shoot a G2V star and calibrate like this. Other shoot a grey and white card in daylight. I need to find a quantitative way to work out the basic R G & B ratios for my QHY8. Then when I shoot in the dark I can have "correct colors" to start with. I don't know. Should I shoot a know subject in broad daylight on 1ms then have a look at the colors and match the ratios this way?

[Merlin66]

I'd recommend going for the G2V star method.
There are plenty of catalogues of these stars available; just make the colour balance adjustments until you achieve a "white" star image.
These settings will give you a "baseline" for your camera and you can always re-check/ validate by comparing G2V stars in later exposures.