EF 85mm f1.8 USM
The EF 85mm f1.8 is a large-aperture lens developed in response to the demand for a portrait lens moderate size and price. It expands the short-telephoto line-up, which includes the EF 100mm f2 and EF 135mm f2.8SF lenses. The use of a wide f1.8 aperture for the 85mm lens means that portraits taken at maximum aperture show a beautiful soft blur effect in the background.
The Lens uses an ultra-sonic motor (USM) for silent, high speed focusing. The 85mm lens takes from 0.2 to 0.4 sec’s to focus from infinity to its closest shooting distance of 0.85m.
Manual focusing is possible at any time while in the AF mode - a wide rubber focusing ring makes focusing easy.
The EF 85mm lens uses a rear focusing system, but not the usual single compensating lens group. Canon has developed and optimised a new optical design for short-telephoto lenses which disperses and compensates aberrations. This is done with two single-element lens groups - a convex and a concave element. The result is an excellent imaging performance, even at maximum aperture.
Focal length and maximum aperture: 85mm f1.8