Hello All, I was wondering what is the reason for the three different metering types? Why are there three different types and is there any special reason for there being three different types of metering. Is spot metering used for portraiture? What is Evaluative metering used for, and is it the same as Matrix Metering? Is center weighted metering for all purpose use? Which came first and what did the past greats use? Thank you in advance for your imput.