A number of respected pros suggested that Daylight wb was a better choice than Auto wb. I being the novice that I am began doing it. I suggested it to another photographer (lesser experienced but more opinionated than the pros who made the recommendations) and he came down on me like Thor's hammer. His reasoning is a raw file is a raw file how that file is captured is of no consequense. Since all involved were shooting raw, I assumed that the capture was somehow affected by usin Auto or Daylight prior to forming the raw file. Can someone explain the reason for using daylight vs auto or is it simply the pros dealer's choice?

The WB selection does not affect the raw data, but it does affect the embedded JPEGs, which are the preview and the thumbnail. A consequence of this effect is, that the WB selection influences the histogram displayed in-camera and the clipping indication, for they are based on the preview JPEG.

Extreme example: if you are shooting in bright daylight and select "incandescant", the histogram may not show any problem, nor does the clipping indication, but the green channels may be horrendeously clipped.

See the related thread Matching RGB histogram with captured RAW data

Thank you Pano. I understand and I read the references that I could find. Some were even understandable. I appreciate your response.

Your friend is correct. The camera WB setting affects only JPEGs that it generates. This is one of the many beauties of RAW - you can worry about WB later.

Peter

simulation credit auto

Really? I didn't know about this