Depth of Field and Abstraction Inspiration

Abstraction: Freedom from concrete ideas and realities, often a representation of a general idea.  In photography, this means straying away from or tweaking the "rules" of design and composition.  Abstract photographs may represent a larger theme or idea, and cause the viewer to observe the photo for some time.

Some Examples:

Derek Mohr

Mohr used an extremely shallow depth of field, and it looks like he used free lensing to create an even shallower depth of field and distortion.  The shallow depth of field and distortion makes this tree a dynamic and interesting subject.

Bill Vaccaro

Vaccaro used a shallow depth and a vignette to emphasize the center of the photo, drawing the viewers' eyes to the tree's branches and trunk.