Canon EF-S lens mount

The Canon EF-S lens mount is a derivative of the EF lens mount created for a subset of Canon digital single-lens reflex cameras with APS-C sized image sensors. It was released in 2003. Cameras with the EF-S mount are backward compatible with the EF lenses and, as such, have a flange focal distance of 44.0 mm. Such cameras, however, have more clearance, allowing lens elements to be closer to the sensor than in the EF mount. Only Canon cameras released after 2003 with APS-C sized sensors support the EF-S mount.

The "S" in EF-S comes from "Small image circle", meaning the lens is designed to provide a small (relative to a normal EF lens) image circle to match the sensor. The smaller mirror used in APS-C cameras also allows optical elements to protrude further into the camera body, which enhances the possibilities for wide angle and very wide angle lenses, enabling them to be made smaller, lighter (containing less glass), faster (larger aperture) and less expensive.

Although not all Canon EF-S lenses use this short back focus, they cannot be mounted on DSLRs with sensors larger than APS-C. However, some lenses produced by third-party manufacturers may feature the standard EF mount if they do not require the shorter back focus but only have a small image circle. Such lenses will give noticeable vignetting if used on a 35mm film or full frame sensor cameras. To a lesser degree, vignetting also occurs with APS-H sensor sizes, such as several (now discontinued) cameras of the 1D series.

Canon EF-S 17–85mm lens

The Canon EF-S 17–85mm f/4–5.6 IS USM is a standard zoom lens for Canon digital single-lens reflex cameras with an EF-S lens mount and image stabilization. The EF-S designation means it can only be used on EOS cameras with an APS-C sensor released after 2003. The field of view has a 35 mm equivalent focal length of 27.2–136mm, and it is roughly equivalent to the Canon EF 28-135mm lens on a 35mm film SLR. Despite the word "macro" being present on the lens body (as visible in the infobox image), this lens is not capable of true 1:1 macro photography.

The 17–85mm was bundled as a kit lens with the EOS 30D, EOS 40D, EOS 50D and EOS 60D. It was also packaged with the EOS 400D (known as the Digital Rebel XTi in North America) as an alternate to the EF-S 18–55mm (typically labeled as the "400D enthusiast's kit").

Similar lenses

The EF-S 17–85mm is a step up in build quality and in focal range compared to the EF-S 18–55mm lens. Its image quality is higher than the original and the Mark II versions of the 18–55mm lens. It is slower and has lower image and build quality compared to the EF-S 17–55mm lens, although it is cheaper and has a longer focal range.

Canon

Canon may refer to:

Places

Religion