Canon EF Lens

Canon is a Japanese multinational corporation known across the globe for its range of imaging and optical products, including cameras, lenses, photocopiers and computer printers. Currently, the Canon EOS range of SLR cameras ranks among the company’s well-known products . The EOS range of cameras used lenses belonging to the Canon EF series. Hence, the Canon EF lenses are also colloquially referred to as "Canon EOS lenses", "Canon camera lenses" or "Canon SLR lenses".

Herein, EF stands for "Electro-Focus", which is derived from the fact that the automatic focusing in Canon EF lenses is done by a dedicated in-built electric motor. In Canon EF lenses, all communication between the camera and the lens takes place through electrical contacts, i.e. the lens does not contain any mechanical levers or controls.

Until recently, the top-of-the-line Canon EF lenses were designated as L-series or "Luxury" lenses. L-series lenses can be recognized by a red ring around the front portion of the lens. Most recent L-series lenses are sealed so as to ensure adequate protection from dust and water. Due to their high optical performance, Canon L-series lenses are widely used by both professionals and serious amateurs alike.

The Canon EF lens range is categorized on the basis of their type into fixed focal length lenses, zoom lenses, tilt-and-shift lenses, macro lenses, image stabilizer-equipped lenses and extenders. Some of the features found in Canon EF lenses include the lens mount index, focusing ring, zoom ring, distance scale window, focus mode switch, focusing distance range limiter switch (found in Canon macro lenses and most longer focal length lenses), image stabilizer switch, autofocus stop buttons, focus preset, filter mounting, etc.

Canon EF lenses also adhere to a loosely specific nomenclature. For example, Cannon EF lenses that come equipped with an image stabilizer have an "IS" attached to their name; these are sometimes casually to as "Canon IS lenses." Similarly, the Cannon EF lenses that come equipped with Canon’s ultrasonic motors have a "USM" attached to their name. In much the same way, Canon EF lenses that feature both an image stabilizer and ultrasonic motor are colloquially referred to as "Canon EF IS USM lenses."

Canon has relatively recently launched a new range of lenses, the Canon EF-S series. The Canon EF-S lens range is derived from the Canon EF lens range, and has been specifically designed for Canon digital single-lens reflex cameras with APS-C sized image sensors. Note that Canon EF-S cameras are compatible with Canon EF lenses. The "S" in EF-S stands for "short back focus" in other words, the rear element of the lens is much closer to the image sensor than in regular 35 mm SLR cameras. This proximity of the rear element to the image sensor considerably broadens the options for wide angle and very wide angle lens. It must be noted that most of the lenses in the Canon EF-S lens range are wide angle lenses.

Among the more peculiar lenses in the Canon EF lens range include the Canon EF 17ñ40 mm f 4.0l USM, 28-105 mm II f 3.5-4.5l USM, 70ñ200 mm f 4.0l IS USM, etc.