The EF lens mount is the standard lens mount on the Canon EOS family of SLR film and digital cameras. EF stands for "Electro-Focus": automatic focusing on EF lenses is handled by a dedicated electric motor built into the lens. Mechanically, it is a bayonet-style mount, and all communication between camera and lens takes place through electrical contacts; there are no mechanical levers or plungers. The mount was first introduced in 1987.
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 Canon EF-S 18–55mm lens f/3.5–5.6 is a Canon-produced wide-angle to mid telephoto zoom lens for digital single-lens reflex cameras with an EF-S lens mount. The field of view has a 35 mm equivalent focal length of 28.8–88mm, and it is a standard kit lens on Canon's consumer APS-C DSLRs. In February 2017 Canon announced the new Canon EF-S 18–55mm lens f/4–5.6 IS STM with a smaller aperture, which made the lens 20% smaller according to Canon.
The EF 16–35 mm lens is a family of professional wide-angle lenses made by Canon Inc. The original version, the EF 16-35mm f/2.8L USM, replaced the EF 17-35mm f/2.8L USM lens, which had itself replaced the EF 20-35mm f/2.8L lens.
The EF 17–40mm f/4L USM lens is a wide-angle lens made by Canon Inc. The lens has an EF mount to work with the EOS line of cameras. Other than the front element, it is sealed against dust and water, and features a diaphragm which remains nearly circular from f/4 to f/8. It is one of the few Canon photo lenses that are parfocal.
The EF 1200mm f/5.6L USM is a super-telephoto prime lens that was made by Canon Inc. It uses an EF mount, and is compatible with the Canon EOS camera range. It has a focal length of 1200 mm and so on a digital body with a sensor size of 22.5 mm × 15 mm, such as a Canon EOS 40D or 450D, it provides a 35 mm field of view equivalent to that of a 1920 mm lens. With a body with a sensor size of 28.8 mm × 19.2 mm, such as a Canon EOS-1D Mark IV, the field of view is equivalent to that of a 1560 mm lens.
The EF 50mm lenses are a group of normal prime lenses made by Canon that share the same focal length. These lenses are based on the classic double-Gauss lens, with the f/1.8 being a standard six-element double-Gauss with an air gap and powers between element 2 and 3 and its faster cousins adding additional elements. The 50mm focal length, when used with a 35mm film or full-frame sensor, has been widely considered to match the perspective seen by the human eye.
The Canon EF 28–135 f/3.5–5.6 IS USM is a "standard" zoom lens that was introduced in February, 1998. The lens has a 4.82x zoom range and is based on the EF Lens Mount and works with all film and digital EOS cameras that support this mount.
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, this lens is not capable of true 1:1 macro photography.
The EF 85mm lenses are a group of medium telephoto prime lenses made by Canon Inc. that share the same focal length. These lenses have an EF type mount that fits the Canon EOS line of cameras.
The EF 24–105mm f/4L IS USM is an EF mount wide-to-telephoto zoom lens. It was introduced by Canon in 2005 to complement the well-regarded 17–40mm f/4L USM and 70–200mm f/4L USM.
The EF 100–400 mm f/4.5–5.6L IS USM is a professional EF mount telephoto zoom lens manufactured by Canon Inc. The first version of this lens was announced in September 1998, and an updated version was announced in November 2014. It is a high performance telephoto lens most often used for sports and wildlife photography.
The EF 500mm lenses are a group of super-telephoto prime lenses made by Canon that share the same focal length.
The EF 200mm USM lens is an L-series prime telephoto lens made by Canon Inc. for the EOS line of cameras. Four 200 mm primes were made: f/1.8, two f/2.8, and the most recent f/2.0.
Canon Inc. has produced seven different 24mm lenses for its Canon EF and EF-S lens mounts. Three have been discontinued after updated replacements were announced.
The Canon Extender EF lenses are a group of teleconverter lenses made by Canon. These lenses are used between any compatible EF type lens and any of the Canon EOS line of cameras. When used with a compatible lens, they will multiply the focal length of the lens by a factor of either 1.4x or 2x, at the cost of decreasing the lens' aperture by 1 or 2 stops respectively. For example, using a 1.4x or 2x extender with the Canon EF 500mm f/4L IS USM would result in a 700mm f/5.6 or 1000mm f/8 lens.
The EF 28–300mm f/3.5–5.6L IS USM lens is a superzoom lens made by Canon Inc.
The EF 35–350mm f/3.5–5.6L USM lens is a discontinued telephoto zoom lens manufactured by Canon.
The Canon EF 8–15mm f/4L Fisheye USM is a fisheye zoom lens for Canon digital single-lens reflex cameras (DSLRs) with an EF lens mount. It delivers 180° diagonal angle of view images for all EOS SLR cameras with imaging formats ranging from full-frame to APS-C, and provides 180° circular fisheye images for full-frame EOS models. Announced by Canon in 2010, it features UD glass for suppression of chromatic aberration and a subwavelength coating for reduced ghosting. It has full-time manual focus for instant switching from AF to Manual operation.
The EF28-200mm f/3.5-5.6 USM lens was a superzoom lens made by Canon Inc.
