Lensbaby adds a twist to its latest special-effects lens, the Burnside 35. In addition to the native swirly bokeh like that of the Twist 60, there's a second aperture with which you dial in the degree of vignetting and saturation.
The lens has a traditional round eight-blade aperture; the effect slider has a polygonal six-blade aperture that overlays the first to cover the edges of the frame.
