Simply put, I have found a light meter to be the best measure of exposure values for any given shot since you can measure light beyond a vertical plane, which I believe is what causes most \"blown\" channels when using the camera\'s metering system. For instance, when you frame a shot, even if you are using evaluative metering, or \"matrix\" metering, wherein the camera uses the whole scene to calculate an average, it is only \"seeing\" a flat vertical plain. In this case, anything on the plain that averages low, will pull the curve to the right, and anything on that plain to the highlight side will pul the curve to the left. Having the ability to meter exactly where you want, and set the exposure accordingly, gives you an advantage......
