The Lensbaby is a bellows style lens for modern SLR cameras. They feature low dispersion multi-coated optical glass lens mounted within a flexible rubber tube to allow the photographer to tilt the lens side to side as well as compress it closer to the camera. Much like cameras from 100 years ago or more focusing is accomplished by simply compressing the bellows to move the lens closer or further away from the camera.What differentiates Lensbabies from other SLR lenses is their selective focus effect. Due to the way that the lens interacts with light at various angles, shots taken with the Lensbaby have a sharp sweet spot with everything else in the image blurring away from that sweet spot. The size and sharpness of the sweet spot is affected by various sized openings internally which are accommodated by interchangeable (and hackable) aperture disks that sit in front of the lens.
Source: lensbabies.comAdded: 19 March 2007