Canon EF 28-90mm lens
The Canon EF 28–90 mm is a full frame SLR zoom lens, also often included as a kit lens with Canon EOS film cameras. The maximum aperture is 4 at 28mm, reducing to 5.6 at 90mm. When set to 90mm, this will create a moderate amount of background blur for portrait photography. There are several versions of this lens. They all share an identical optical design of 10 lenses in 8 groups and 5 aperture petals. Versions I and II were available with either a DC auto focus motor or an  ultrasonic USM motor. All other differences are purely cosmetic. All versions had plastic lens mounts and barrels. Some were available in silver or black colour. The lens is a very lightweight design, and has fast auto focus even without USM. Image quality suffers, though, particularly between 28–35mm and 80–90mm, and there is heavy vignetting when used wide open. For digital EOS cameras with APS-C sensors, the EF-S 18–55mm lens covers the same focal length range. This is due to crop factor. EF-S lenses only work with Canon 1.6x crop cameras, which results in an  angle of view roughly equivalent to that of a 29–90mm lens on a 35mm camera. Like the 28–90mm, the 18–55mm is also a kit lens.