General wide-angle prime is designed for full-frame Canon EF-mount DSLRs, however can also be used with APS-C models where it provides a 56mm equivalent focal length.

Unique optical design features six multi-coated elements in four groups, and is designed to produce imagery with a large area of central sharpness surrounded by distinct, swirly bokeh and pronounced vignetting.

Dual diaphragm design incorporates a primary six-blade diaphragm to control exposure and to introduce the desired amount of swirly out of focus in the image, with larger apertures producing the smallest in-focus area and most swirl and smaller apertures producing a larger in-focus area with minimal swirl.

Secondary eight-blade diaphragm can be adjusted using the bronze effect slider on the side of the lens barrel, and is used to control the amount of vignetting as well as the quality of the bokeh in the out-of-focus areas of the image. When wide open, the swirl quality will be softer and when closed down, there will be greater detail in the swirl and more vignetting will be apparent.

Manual focus design with a smooth, dampened focusing movement is complemented by engraved focus distance indicators.