I'm a newbie using a Rebel 300D. I think I have a basic grasp of the metering modes of the camera, and I want to use AE lock to get correct exposures of subjects taken with two 500W hot lights w/white umbrellas against mostly light paper backgrounds.
Is it OK to move in to a closer distance than the shot will be taken at to fill the frame with the subject (or particular area of the subject), set AE lock at this distance, and then take the shot at a further distance? The reflected light would be more intense at the closer distance; wouldn't this result in an incorrect exposure when moving back? I'm assuming one would focus on the subject when taking the AE reading, set AE lock, and focus again when shooting.
I have GM white and grey cards. The grey card has white, grey and black bands. I have been using this card, placed near the subject, to set AE lock before shooting by just filling the frame with the card. Usually I don't use custom WB.
My results tend to look flat and sometimes washed out, but the histograms usually don't indicate excessive clipping. Sometimes mid tones and darker colors appear exaggerated and oversaturated, but detail seems to be there.

