The Sweet 35 Optic is a 35mm, selective focus optic with a 12-blade adjustable aperture that provides unprecedented creative control over the size of the sweet spot and the amount of blur.This is the widest focal length selective focus Lensbaby optic currently available, and the first to feature an adjustable, internal aperture. Rotating the aperture dial on the front of the lens changes between apertures from f/2.5 through f/22. The Sweet 35 Optic is part of the Lensbaby Optic Swap™ System.The Sweet 35 Optic, compatible with the Composer, Muse, Control Freak, Scout and Composer with Tilt Transformer* lens bodies, produces a sweet spot of focus surrounded by a smooth, gradual blur. The Sweet 35 Optic provides photographers with even more creative freedom to capture their vision in camera by dialing in the sweet spot quickly and seamlessly, in the moment.The Sweet 35 is an incredibly versatile optic, allowing photographers to focus anywhere from 3-7.5” from the front of the lens to the subject, depending upon which lens body is being used. Its wide 35mm focal length is perfect for landscape, event and environmental portrait photography. Want to see even closer? Add on the Lensbaby Macro Converter.The Sweet 35 has 46mm threads so it is not compatible with the other Lensbaby Accessories because they have 37mm threads