In April 2014, the cumulative production of Canon's "EF lenses" broke the 100 million record. How did the new mount system win the trust of photographers with mechanical control completely eliminated from the traditional FD mount? Part 2 of the series tells you more about the history of the evolution. (Reported by: Kazunori Kawada)
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Phase 2: Growth Era - Advent of the Digital Age
In April 1991, three TS-E lenses (24mm, 45mm, and 90mm) were released, all of which were built in with a shift mechanism in addition to tilt control. The greatest breakthrough, however, was the introduction of an automatic aperture control system on a tilt-shift lens for the first time. For tilt-shift lenses, which allow bending of the optical axis, it was difficult to move the aperture system mechanically from the camera body. Until then, the conventional practice was to set focus at the maximum aperture and perform the necessary tilt-shift adjustments before stopping the aperture down manually to the desired value. The TS-E lenses, in contrast, employ an "Electro-magnetic Diaphragm (EMD)", which is equipped with an actuator on the lens for driving the aperture, thus enabling automatic aperture control even when the lens is tilted or shifted. When manual aperture adjustment was necessary, I often forgot this step during shooting, and ended up with significantly overexposed shots. Such blunders no longer occurred with the automatic aperture control of the TS-E lenses. This has been made possible, thanks to the adoption of a fully electronically-controlled mount with mechanical control fully eliminated on the lens mount. While beginners in photography might not be familiar with the TS-E lenses and the tilt-shift function, they are essential items among professional photographers specialising in architectural, interior, or merchandise photography. The effort to include such lenses for the niche market in the EF lineup is one of the reasons why professionals place great trust in Canon's products.
EF Lens Feature 1 - Image Stabilizer (IS)
Canon was the first to successfully introduce the Image Stabilizer for commercial use on interchangeable SLR lenses. The basic mechanism remains unchanged today, with a number of gyro sensors used to detect camera shake, which is then offset using a corrective optics system.
In 1995, Canon launched the "EF75-300mm f/4-5.6 IS USM" lens, the world's first interchangeable lens for SLR cameras to be equipped with the "Image Stabilizer (IS)" feature. The IS functions by detecting camera shake with gyro sensors, and offsetting the shake by moving the lens group for corrective optics with an effect equivalent to about two shutter speed stops. Users were enthralled by the appearance of this handy feature that they had longed for, as it helped to free photographers from the hassle of using tripods when shooting in low-light scenes. Ever since, the IS feature has been adopted on EF lenses that were subsequently released. Besides the IS lenses, Canon is also the first to successfully commercialise the use of many other types of lenses in its EF series, such as those that are solely made up of environmentally-friendly lead-free glass elements, and "DO lenses" built in with a "Multi-layer Diffractive Optical Element", which helps to achieve a compact and high-performance design.
Historic EF Lens 1 - EF75-300mm f/4-5.6 IS USM
This is the first lens to be built in with the Image Stabilizer (IS) feature, which amazingly offsets camera shake that occurs during telephoto shooting with a corrective effect equivalent to about two shutter speed stops. This feature has won the support of many professionals and enthusiasts for its ability to reduce the number of unsuccessful shots.
EF Lens Feature 2 - Multi-layer Diffractive Optical Element (DO)
- Single-layer Diffractive Optical Element, Diffraction Grating
- 3-layered DO Lens
- Incident Light (White Light)
- Superfluous diffracted light occurs
- Almost all of the incident light is now usable for shooting
- Diffracted light usable for shooting
- Diffracted light that causes flare
DO lens elements are capable of controlling the light path by employing the phenomenon of light diffraction, which occurs when light passes through the edge of an obstructing object.
A compact and high-performance design is achieved with the characteristics of a fluorite lens and an aspherical lens combined into a single element.
Historic EF Lens 2 - EF400mm f/4 DO IS USM
With the employment of a DO lens element, Canon succeeded in developing this compact and lightweight lens, which boasts amazing specs with a small aperture of f/4 and a telephoto focal length of 400mm. The EF400mm f/4 DO IS USM is particularly useful when mobility is required, such as in sports photography. The IS feature is also built in to ease handheld shooting.
Timeline of EF Lenses - Part 2 [August 1995 to January 2006]
Total production of EF lenses hits the 10 million mark
Releases the "EF28-80mm f/3.5-5.6 III USM" which comes with a new coating
Releases the "EF75-300mm f/4-5.6 IS USM", the world's first interchangeable lens for 35mm format SLR cameras to be equipped with the Image Stabilizer feature
EF75-300mm f/4-5.6 IS USM
Releases the "EF28mm f/1.8 USM", which uses a replica aspherical lens element
Releases the "EF400mm f/2.8L II USM", which employs a new optical design with the use of fluorite and UD lens elements to correct residual chromatic aberration
Releases the "EF180mm f/3.5L Macro USM", which is built in with an inner floating system, the "EF17-35mm f/2.8L USM", which employs two aspherical lens elements, and the "EF135mm f/2L USM", the lightest lens among those in the same class
Releases the lead-free "EF28-80mm f/3.5-5.6 IV USM", and the "EF24-85mm f/3.5-4.5 USM", which adopts a multi-group movable zoom system and a replica aspherical lens element
Releases the "EF300mm f/4L IS USM", which employs UD lenses as the second and fifth element
Releases the "EF24mm f/1.4L USM", the first EF lens to employ both ground and polished aspherical lens and UD lens elements, and also the first lead-free L lens
Releases the "EF28-135mm f/3.5-5.6 IS USM", a compact lens that is equipped with a newly-developed IS unit and a multi-group movable zoom system
Releases the "EF22-55mm f/4-5.6 USM", which employs an aspherical lens element to achieve a compact design, and the "EF55-200mm f/4.5-5.6 USM", which enables silent and high-speed AF with the use of a micro USM
Releases the "EF100-400mm f/4.5-5.6L IS USM", the first L lens to be built in with the IS feature, as well as fluorite and super UD lens elements
Releases the "EF35mm f/1.4L USM", which employs a rear-focusing system with the use of a ground and polished aspherical lens element
Releases the "EF28-80mm f/3.5-5.6 V USM" and the "EF75-300mm f/4-5.6 III USM", which adopt a new high-grade and lead-free design
Releases the "EF300mm f/2.8L IS USM" and the "EF500mm f/4L IS USM", a model changeover to include the IS feature and the high-speed AF and AF stop functions
Releases the "EF70-200mm f/4L USM", which boasts high image quality with the use of fluorite and UD lens elements, the "MP-E65mm f/2.8 1-5x Macro", which supports macro shooting from life size to 5x magnification, and the "EF400mm f/2.8L IS USM" and the "EF600mm f/4L IS USM", two IS lenses that enable high-speed AF
Releases the "EF100mm f/2.8 Macro USM", which achieves silent AF with the use of a ring USM, and is the first mid-telephoto macro lens to be built in with an inner focusing system
Releases the "EF28-90mm f/4-5.6 USM", which adopts a new design for a wider telephoto focal length range and an aspherical lens element for enhanced image quality, and the "EF28-200mm f/3.5-5.6 USM", which achieves high image quality with the use of two aspherical lens elements while boasting a long telephoto focal length
Releases the "EF28-105mm f/3.5-4.5 II USM", which supports high-speed AF and full-time MF with a mechanical unit that is equivalent to the predecessor models
Total production of EF lenses hits the 20 million mark
Releases the "EF70-200mm f/2.8L IS USM", a telephoto zoom lens equipped with the IS feature
Releases the "EF16-35mm f/2.8L USM", an anti-dust and water-resistant lens with a wider angle
Releases the "EF400mm f/4 DO IS USM", a compact and lightweight lens that employs a "Multi-layer Diffractive Optical Element (DO)" as part of the optical system on an interchangeable lens for 35mm format SLR cameras
EF400mm f/4 DO IS USM
Releases the "EF28-105mm f/4-5.6 USM", which is equipped with the newly-developed Micro USM II, the "EF28-90mm f/4-5.6 II USM", which boasts the highest AF speed when used with the EOS 300V, and the "EF90-300mm f/4.5-5.6 USM", which adopts a circular aperture design
Releases the "EF24-70mm f/2.8L USM", which adopts a new design to achieve a wider angle, and an aspherical lens and a UD lens element for enhanced image quality
Releases the "EF17-40mm f/4L USM", which has a wider zoom range and is built in with an aspherical lens and a super UD lens element for enhanced image quality
Releases the "EF28-90mm f/4-5.6 II" and "EF90-300mm f/4.5-5.6", which achieve high-speed AF with the use of an ultra-compact DC motor, and the "EF55-200mm f/4.5-5.6 II USM", which reduces flare and ghosting by optimising the coating
Releases the "EF28-300mm f/3.5-5.6L IS USM", a super zoom lens built in with the IS feature and an extended zoom range on the wide-angle side, and the "EF70-300mm f/4.5-5.6 DO IS USM", which achieves a compact design and reduces flare and ghosting with the use of a Multi-layer Diffractive Optical Element
Releases the "EF28-90mm f/4-5.6 III" for the EOS 300X and EOS 3000V, the "EF-S17-85mm f/4-5.6 IS USM", the first EF lens to be equipped with a glass-moulded aspherical lens element that has aspherical surfaces on both sides, and the "EF-S 18-55mm f/3.5-5.6 USM", the first EF-S lens and also the kit lens of the EOS 300D that can be purchased separately
Releases the "EF-S10-22mm f/3.5-4.5 USM", which employs an aspherical lens and a super UD lens element
Releases the "EF-S18-55mm f/3.5-5.6 II USM" and the"EF-S60mm f/2.8 Macro USM"
Releases the "EF70-300mm f/4-5.6 IS USM" and the "EF24-105mm f/4L IS USM"
Total production of EF lenses hits the 30 million mark
(EF70-200mm f/2.8L IS USM)
EF70-200mm f/2.8L IS USM
Born in Kanagawa Prefecture in 1961. After working four years as an assistant to photographer Koichi Saito, Kawada became a freelance photographer in 1997. Currently, his works centre on shoots and review writing for camera magazines and other publications.