Point your camera at a subject, check the meter, and press the shutter release button. The camera clicks. Later, you review your shots on the camera’s LCD display and take a look at the histogram. Both the meter and histogram show you versions of how your images are exposed and both are quite useful. But while they do have a lot in common, they work quite differently. This week we’ll take a look at how they compare.
The meter registers whatever you point it at. It only knows what it sees right now and has no memory or what you pointed it at even a moment ago. It also doesn’t see anything outside its field of view, an area that may not even cover the entire frame depending on how you have it set. As a spot meter, it may only see a one degree circle in the center of the frame, totally oblivious to whether anything beyond that is over or underexposed. Even on matrix or “evaluative” metering, the whole frame may factor in to the exposure calculation, but not every part equally. It does all this in an attempt to help you emphasize what you think matters most in a shot while not totally neglecting everything else.
