Lensbaby's Sweet 35 Optic is a 35mm optic with a 12-blade diaphragm and adjustable aperture (f2.5-f/22) that gives you unprecedented precision control over the "sweet spot" of focus in your selective focus photos. This is the widest focal length of any Lensbaby selective focus optics--the Sweet 35 also has close-focus capabilities. It's part of the Lensbaby Optic Swap System. Use it with the Lensbaby Composer, Scout, Muse, or Control Freak lens body--just rotate the dial on the front of the optic to quickly change the size of your in-focus "sweet spot".