Metering/Exposure questions

[Tom Camilleri]

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.

[PacAce]

You shouldn't have any problems setting the exposure by getting closer to the subject and then taking the reading. Or, if you're going to be using teh AE lock which makes use of the partial metering circle in the center of the viewfinder, you can just move in close enough for the subject part you want to meter on to fill that circle. Just make sure that you don't cast your own shadow on the subject when you move in closer since that'll change your reading for sure. Just remember that if you do use the AE lock, you have to take the shot in so many minues (forget how many, though).

[Tom Camilleri]

Thanks! I was getting confused over this, but I think I understand now. What was throwing me is that the reflected light intensity drops off with the square of the distance from the subject. If you move in to use AE lock, the light becomes more intense so how could the exposure set at a closer distance work? I hit me that in setting the exposure the camera is trying to correctly reproduce what you are looking at, and nothing more. If I'm understanding this right, as long as he camera responds to light at various distances the same as the human eye, setting exposure up close will work.

[scottbergerphoto]

Reflected meters like your camera's are designed to take readings from any distance. Just make sure as Leo said that you fill the partial metering circle with the area you want to expose properly. You could take a reading across the street with a 500mm zoom as long as the subject area filled the partial metering circle.
Scott