Canon 40D

[jim t]

Should I set my 40d to capture in sRGB or Adobe RGB?  

I edit in Pro RGB in PS.  Also shoot mainly RAW.

[james_elliot]

Should I set my 40d to capture in sRGB or Adobe RGB?  

I edit in Pro RGB in PS.  Also shoot mainly RAW.

If you shoot Raw, there is no difference. Just set the correct colorspace output when converting your RAW files.
The colorspace set in camera is just used for JPEGs.

[Panopeeper]

1. For JPEG, set that color space, what you will need later, most probably sRGB.

2. For raw: the "truthfulness" of the displayed histogram and flashing clipping indication depends on the color space. If you are shooting ETTR consequently, with total neutral settings, then you should use sRGB, otherwise the histograms and clipping indication may not show overexposure correctly.