Quote Originally Posted by pnodrog View Post
Needing to adjust the magenta/green axis indicates you have a problem.
Hi Paul,

In theory a magenta/green axis movement is reserved for the likes of non-continuous spectrum light sources as you mention - unfortunately - (a) that also includes fluorescent tubes and (b) studio strobes. In my case (in the studio) I usually need a shift on this axis of -7 and I've seen it even go higher than -12 on occasions. It's not a problem though because the adjustment is available. I just wanted to mention it because if one uses a "kelvin" approach as per the article then one will be S-O-L, which is why I thought the article offered some advice that I thought wasn't "best practice".

With the blue/yellow colour temperature axis you will often be lucky enough to be dealing with a black-body or incandescent light source that will have a reasonably continuous spectrum and a colour temperature adjustment should work fairly well. Unfortunately needing a magenta/green axis adjustment indicates you are dealing with a noncontinuous spectrum light source that will have a mix of bands of colour. It is unlikely you will be able to do an adjustment that will keep a true relationship between all the colours in an image. The WB compromise will inevitably be far greater with these light sources and may never be satisfactory. (The dress was not that colour - my handbag should match my scarf)
Keeping a true relationship is impossible - but - custom colour profiles go a long way towards correcting the problem.

In the field I leave the camera on Auto WB shoot RAW, concentrate on subject, exposure, focus and composition and then worry about the final colour correction later in the comfort of a chair. I think Colin and many others do the same.
That's me On location I - if I'm wanting "accurate" WB I just leave it on auto. If I'm on location shooting landscape then I'll just adjust for whatever looks best - it doesn't affect the RAW shot anyway, but does give me a better idea as to whether or not my exposures are in the ballpark with regards to colour saturation. In the studio it's set at 4800 because that's the closest to what it is, and looks best on the tethered monitored.