This 18mm Compact Prime lens features an improved optical design over the CP.2 variant and shares the same physical length as the 15, 21, 25, 28, 35, 50, and 85mm CP.3 lenses while maintaining identical focus and iris gear positioning with the entire set of CP.3 lenses, relative to the mount. All CP.3 lenses also share the same 95mm front diameter. Similar physical attributes across the lens line makes fitting lens accessories such as matte boxes, follow focuses, lens supports, and lens control motors easier and less time consuming.

Another feature handed down from the preceding CP.2 lenses is the interchangeable mounts. This lens comes with a PL mount installed. Though, if you wish to fit your CP.3 lens to a different camera, the lens mount can be swapped by the user for a separately available mount of a different kind. If you like the bokeh in your images to be round, even after stopping down, you will be pleased to know that the 14-bladed iris from the CP.2 has not been left out of the optical design.