The 5D Mark III offers four different metering modes by which the light of the scene can be measured to help you achieve an accurate exposure. Evaluative metering does much of the heavy lifting for my photography. Even in relatively complicated lighting situations, I’ve found that evaluative metering does a great job in giving me accurate exposures. When I don’t like the result it’s giving me, I often use the exposure compensation feature to increase or decrease the exposure and achieve the look that I’m going for. However, I sometimes use the partial, center-weighted average (Figure 4.4), or spot meter when I want to emphasize my subject for the basis of my exposure.
Figure 4.4 This low-light scene was illuminated by a few lamps and called for metering the scene using center-weighted average metering to ensure a good exposure for this interaction between man and cat.
If I have a severely backlit subject, which means the area behind the subject is considerably brighter, I may use the partial, center-weighted average, or spot mode to isolate the exposure on my subject. This may result in the background being blown out or overexposed, but if the background is of little importance, I’ll be okay with that. I want to make sure that my subject is well exposed in order to retain the important details of the face.