IF YOU'VE checked out Instagram lately, you know that tilt-shift photos are all the rage. These are the images with one portion in sharp focus and the surrounding area blurred. The effect is a simple way to spice up an otherwise run-of-the-mill portrait or a landscape shot, letting you highlight the face of a sleeping baby or draw attention to a detail on a busy street.

While smartphones make applying the effect as easy as tapping a touch screen, to take a true tilt-shift photograph, you basically have two choices: pay $300...