All about Composition and your Camera
Emphasis is the art of introducing proportion : making words, sounds, things of importance, stand out against a surrounding of comparative indifference. In photography it is the art of centring all interest on one particular quality of the subject. It is this emphasis - where we put it, how we put it and with what - which will make a photograph an individual piece of human work as distinguished from a dull example of mechanical reproduction.
How to emphasis, pronounce, under-score some part of the picture made by a camera? There are ways : we can differentiate by comparative sizes, we can render sharp or un-sharp, we can distribute light and shade. We can play all these cards together or just one of them at a time.