A Brief History of Canon SLR Lens MountsIn May of 1959 Canon introduced its very first single lens reflex (SLR) camera, the Canonflex. Since the advent of interchangeable lenses, there has also been the need to find the best way to attach the lens to the camera. Canon has developed a number of lens mounts thru the years and this article will attempt to chronicle the history of the Canon lens mount and hopefully clear up any questions that you may have. If not please feel free to contact us and we will try to resolve any issues you may still have.
Canon R Lens Mount
1959 - 1964
Canonflex Camera Canon R Lens Mount
The Canonflex introduced what was to become the famous Canon breech lock or spigot-mount. The lenses have two pins at the rear that act as a cocking and stop down mechanism when the film is advanced and the shutter is released. If you advance the film without the lens on the camera, the mechanism is not cocked and the lens does not work properly. The selling point is you always have a secure mount because the lens-body mating surfaces do not slide against each other when mounting and therefore cause no wear on the surfaces. In reality, this system took noticeably longer to attach or remove lenses. Worse, the extended pins and levers were unprotected without a rear lens cap.
Canon FL Lens Mount
1964 - 1971
Canon FX Camera Canon FL Lens Mount
The R series lens was replaced in April of 1964 with the release of the Canon FX camera with the new FL lens mount. The FL-series lenses along with the FX camera were designed to achieve smooth coupling between the camera body and lens. The two-pin system was replaced with a single operating pin at the rear. The new lenses could be used on the R series cameras and the R series lenses can also be used on FL series camera bodies. Most FL lenses have a depth of field preview system to allow using the senses in preset mode on R series bodies. In the 1960's, the Through the Lens (TTL) metering system was developed and introduced on the Pellix in 1965 and the FT QL in 1966. This system permitted measuring only the light in the field of the lens.
Canon FD Lens Mount
1971 - 1976
Canon F-1 Camera Canon FD Lens Mount
In March of 1971, the next generation of lens mount was released with 14 new FD series lenses. This series of lenses was designed with the upcoming Auto-Exposure (AE) in mind as well as the coming optical electronics age. Unlike the FL-series lens equipped with a single automatic diaphragm pin, the FD-series lens was notable for its single pin for transmission of the lens' maximum aperture, allowing full aperture metering. Such specification became a mainstream in the era of the electronic camera. With the development and release of the FD series Canon set new, higher standards for their lenses. The guidelines set forth at that time have remained the underlying concept for the development of all Canon lenses to this date.
New Canon FD Lens Mount
1976 - 1987
Canon AE-1 Camera New Canon FD Lens Mount
As the automatic exposure (AE) control system evolved so did the FD series of lenses. Phased in around 1976 with the release of the AE-1 the most noticeable change was the introduction of the bayonet style of mounting. The original FD lenses had a chrome breach lock ring that was tightened down to mount the lens. To meet demand for a faster and easier lens mount Canon developed the line up the dots and twist bayonet system that retained interchangeability with earlier cameras.
Canon EOS Lens Mount
1987 - Present
Canon EOS 620 Canon EF Lens Mount
With the development and release of the first Canon EOS camera, the EOS 620 in 1987, came the need for an entirely new lens mount. The EF series lens had the largest internal diameter of any lens system used with 35mm SLR cameras. The large aperture made this the brightest lens in the world. This was also the introduction of the autofocus system for Canon cameras. It was a revolutionary system because unlike other autofocus lenses of the time the motor to drive the autofocus was in the lens and not the camera body. This meant that only electronic contacts between the camera and lens were needed and not mechanical ones. The mounting system was then simpler and more durable. The EF series has grown into a mature system with over 70 lenses for all types of applications. Advancements to the line since its inception include the Ultrasonic Motor (USM), Image Stabilizer (IS), Diffractive Optics (DO), and using fluorite and aspherical elements in the construction of the L-series lenses for superior image quality.
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