Quote Originally Posted by benjiboy View Post
If that's the case Mark you only need to take one normal incidental reading pointing the dome from the subject to the camera and not overcomplicate things
The more I think about this, the more I keep falling back to pointing the meter at the camera.

I say this because that relationship to the camera defines a very specific point on the film's curve. Every other position is a guess, albeit they might be good guesses, but they are still guesses.

Quote Originally Posted by benjiboy View Post
if you're shooting a girl in a white dress against a light background reduce exposure by half a stop, and conversely if she has a dark dress against a dark background open up half a stop, otherwise in normal circumstances just follow the meter reading.
I understand that this is the classic idea but this is a decision that redefines what the subject is (is it the face or the dress?) and I think it's a hold-over from slide shooting. I don't know that this is a necessary step when shooting the Delta 400 (or another negative film) like this shot was done with.

Quote Originally Posted by benjiboy View Post
In my experience Incidental metering gives an uncannily high proportion of correct exposures for normal subjects other than distant landscapes, sunsets, and stained glass windows without having to do the mental gymnastics that are required by some reflected light metering systems.
I agree heartily here.

Quote Originally Posted by benjiboy View Post
P.S The Duplex System requires one reading to be taken pointing the dome at the light source ( outdoors the Sun) in the studio at the mainlight, and the other from the subject to the camera in the normal way and the two readings averaging.
Duplexing as you describe it here makes more technical sense now, one classic reading plus one reading pointed at the light source averaged would protect the highlights.

I could see using this method with slides, but I don't shoot slides much.