I was on dpreview reading about the 1Ds and it mentioned the camera had a white balance sensor. I had never heard of that feature before. So I looked at the new 1D/1Ds Mark III and I didn't see where they had a white balance sensor. I'm assuming this feature didn't work and was discontinued?
The white balance sensor on the original 1D and 1Ds is simply an aid to the existing AWB system (which is primarily based on the image read from the sensor). With the Mark II cameras, Canon apparently decided that the AWB was "good enough" to do away with the separate sensor. AFAICT, the AWB performance of the Mark II is equal to or better than the Mark I cameras.
In my experience, the AWB sensor affected the colors in a bad way as in most cases the light falling on the subject has a different color temperature than that at the camera position. For instance, if you have the sun behind you, the subject is in the sunlight while the sensor is in the shadow. It was a good move from Canon not to continue with it. I find the AWB on my 1Ds2 much better than the 1Ds.
