Lensbaby 0.42x lens
Like the current line of Lensbaby accessory lenses (which includes a 1.6x telephoto, 0.6x wide angle, and +4 and +10 macro filters), the 0.42x Super Wide Lens simply screws onto the front of any Lensbaby lens via its standard 37mm screw thread. The 0.42x Super Wide Lens converts Lensbaby optics from a 50mm focal length to an ultra-wide 21mm focal length.
Reviews Lensbaby Super Wide Angle