Originally posted by CJC Thank you for the excellent insight. I questioned the original post because I am paranoid about overexposure in digital so now I understand your reasoning. Underexposure is preferable to overexposure. In wedding photography, I am constantly seeking to balance the detail in an expensive gown with the skin tones of the bride. Question: If I point the meter at the brightest spot on a white gown, that then is middle grey and I still will open up two stops exposing that perfectly? Skin tones will then be somewhat underexposed in that scenario. Correct?
Well, the game is to expose to the right, so that you'll have the most data to retrieve (including from the shadows).
By exposing correctly for the detail in white, you make sure this happens. A spotmeter on the dress is the way of shutting out the rest of the scene that might confuse your camera (bit like spotmeter under the chin in a portrait).
The opening up two stops will make sure the dress stays white instead of turning grey. You can always bring up the face in post if you don't want it to fade by comparison.
If instead you exposed for the face first time round, you might blow the dress highlights, which was what you were fearing. Neil van Neikerk goes through all this in his book and (Adorama??) video.
You can always look at the histogram after the shot to confirm your choice.