I was perusing my Google Reader today and found something I think is a great example of edges in a realistic style painting. Faith Te is a wonderful realist artist from the Philippines. Her post today isn't a landscape -- it's a still life of grapes. But look at those edges! The crispest edge lets you know right where the center of interest lies. The other edges are soft (not blurry, which is too easy to do) and lost just where they are supposed to be lost.
Here's a link to Faith's blog, full of other wonderful stuff:
Faith Te's blog