Pairing a cherished short-telephoto focal length with an exceptionally bright maximum aperture, the Canon RF 85mm f/1.2L USM is also characterized by its advanced optical design to produce well-corrected imagery. The fast f/1.2 design excels in difficult lighting conditions and also benefits working with shallow depth of field and selective focus techniques. The optical layout incorporates a Blue Spectrum Refractive Optics element; a specially developed element that helps to nearly eliminate chromatic aberrations and colour fringing for notable clarity and colour accuracy. In addition to this, an ultra-low dispersion element and one aspherical element are also featured to further control various aberrations and distortion for great sharpness and resolution. Individual elements also feature an Air Sphere Coating to suppress flare and ghosting for high contrast and color fidelity when working in bright and backlit conditions.

Complementing the imaging capabilities is an apt ring-type Ultrasonic Motor, which delivers fast, near-silent autofocus and full-time manual focus override. A unique Control Ring is also integrated into the lens design for intuitive control over exposure settings from the lens itself.