I am totally confused about what to do with these metering modes. I have the basic 4 metering modes in my camera (Canon 60D) (Evaluative, partial, spot, center-weighted) Does this help with properly exposing my photos? If it's supposed to help measure the brightness of the subject, then how do I know which mode I should be picking? Also, I'm reading a book called "Understanding Exposure" by Bryan Peterson, if anyone's read this book can you explain what he means when he often refers to "taking a meter reading, getting a correct exposure at a particular aperture, and then recomposed and took the shot". How do you recompose a shot without totally messing up the exposure triangle? Thanks, I hope these questions make sense.