This Lensbaby Double Glass Optic is part of the Lensbaby Optic Swap System - a line of camera lenses that incorporate a simple lens with a bellows or ball and socket mechanism for use in special-effect photography. It is fully compatible with Lensbaby Composer, Muse, & Control Freak Lenses.
The Double Glass Optic mounts to the front of the lens to provide an extremely sharp "sweet spot" with surrounding areas appearing diffused or out of focus. The Double Glass optic is multi-coated optical glass and has a high refractive index. It can be interchanged with the Muse, Composer, and Control Freak lenses to provide artists with an almost unlimited variety of looks and styles to capture their unique visions.