What is the Canon EOS System?

The Canon EOS (Electro-Optical System) autofocus 35 mm film and digital SLR camera system was introduced in 1987 with the Canon EOS 650 and is still in production as Canon's current dSLR system. The acronym EOS was chosen for Eos, the Titan Goddess of dawn in Greek mythology, and is often pronounced as a word (i.e., EE-oss), although some spell out the letters. There is no officially correct pronunciation, as both seem logical.

Cano EF EOS Lenses

It competes primarily with the Nikon F series and its successors, as well as autofocus SLR systems from Olympus Corporation, Pentax, Sony/Minolta, and Panasonic/Leica. In most countries, EOS cameras have the largest market share of SLR cameras.

At the heart of the system is the EF lens mount, which replaced the previous FD lens mount.

The EF lens mount

Main article: Canon EF lens mount

The bayonet-style EF lens mount is at the center of the EOS camera system. Breaking compatibility with the earlier FD mount, it was designed with no mechanical linkages between moving parts in the lens and in the camera. The aperture and focus are controlled via electrical contacts, with motors in the lens itself. This was similar in many ways to Nikon's 1983 F3AF (and to many of Nikon's more recent autofocus lenses), although other manufacturers including Contax (with its G series of interchangeable-lens 35 mm rangefinder cameras) and Olympus (with its Four Thirds System) have since embraced this type of direct drive system. The bayonet-style mount 14mm F2.8 L lens TS-E 24mm f/3.5L lens 50mm F1.4 lens 85mm F1.2 L lens 100mm F2.8 macro lens 135mm F2 L lens Canon EF 400mm lens 16-35 F2.8 L lens 24-70 F2.8 L lens 70-200mm F2.8 L lens 70-300mm F4.5-5.6 IS DO lens

EOS flash system

Main article: Canon EOS flash system The flash system in the EOS cameras has gone through a number of evolutions since its first implementation. The basic EOS flash system was actually developed not for the first EOS camera, but rather for the last high-end FD-mount manual-focus camera, the T90, launched in 1986. This was the first Canon camera with through-the-lens (TTL) flash metering, although other brands had been metering that way for some time. It also introduced the A-TTL (Advanced TTL) system for better flash exposure in program mode, using infrared preflashes to gauge subject distance.

This system was carried over into the early EOS cameras wholesale. A-TTL largely fell out of favor, and was replaced by E-TTL (Evaluative TTL). This used a pre-flash for advanced metering, and used the autofocus system to judge where the main subject was for more accurate exposure. E-TTL II, which was an enhancement in the camera's firmware only, replaced E-TTL from 2004.

Canon Speedlite-brand flashes have evolved alongside the cameras. They are capable of wired and wireless multi-flash setups, the latter using visible or infrared pulses to synchronise.

Speedlite 550EX Speedlite 430EX

EOS cameras

As of 2007, Canon has released no fewer than 40 EOS SLR camera models, starting with the introduction of the EOS 650 in 1987. In the 1990s, Canon worked with Kodak to produce digital camera bodies, starting with the EOS DCS 3 in 1995. The first digital EOS SLR camera wholly designed and manufactured by Canon is the EOS D30, released in 2000.

Canon has also released two EOS cameras designed to use the APS film format, the EOS IX and the EOS IX Lite.

There is also a manual-focus EOS camera, the EOS EF-M. It comes with all the automatic and manual exposure functions but lacks autofocus. However, it comes equipped with a split-screen/microprism focusing screen for precise manual focusing.

Eye-controlled focusing

Through the tracking of eyeball movements, EOS cameras equipped with eye-controlled focusing (ECF) are able to choose the appropriate autofocus point based on where the user is looking in the viewfinder frame. ECF comes especially useful in sports photography where the subject may shift its position in the frame rapidly.

ECF is a function that is usually either loved or hated. Some users feel that it is not reliable enough for common use. Others report that they are able to use it reliably. Much of this depends on the user. Eyeglasses can also reduce its accuracy for some.

EOS cameras equipped with ECF are the EOS A2E (U.S. model names are shown; see the table below for equivalents in other countries), EOS Elan IIE, EOS IXe, EOS-3, EOS Elan 7E, and EOS Elan 7NE.

Quick control dial

Quick Control Dial on EOS 100Most prosumer and professional level EOS cameras feature a large quick control dial (QCD) on the camera back. Allowing easy operation of the camera using the thumb, the QCD is used for quick access to often-used functions that may otherwise require a more complicated procedure of button-presses and dial-clicks.

Cameras equipped with the QCD can easily be operated with one hand (forefinger on the main dial, thumb on the QCD) without taking the eye off the viewfinder.

Some useful functions that a QCD is programmed to do include setting exposure compensation, setting of aperture in manual exposure mode and scrolling of images and menus in digital EOS cameras.

Multi-point autofocus system

The top-line EOS cameras have up to 45 autofocus (AF) points, the most in their class, until superseded by Nikon's D3 and D300 digital SLR cameras with 51 autofocus points. This increases the chances of a sharply-focused photograph in situations where the subject travels across the frame at high speeds, e.g. sports, birds. The number, type, features and performance of autofocus point array systems is likely to continue to evolve.

Having so many AF points also helps relieve the photographer from having to use the 'lock focus and recompose' method of framing a photograph, since the subject will most probably have been picked up by one or more of the AF points. Even though the camera is intelligent enough to select the correct AF point(s) most of the time, EOS cameras equipped with a multi-point AF system will still allow the photographer to manually select an AF point.

EOS-3, EOS-1v, and the EOS-1D family feature a 45-point AF system. With the exception of EOS 1000D, all Canon DSLRs introduced since late 2005, starting from the EOS 20D and the Rebel XTi (400D) feature a nine-point AF system in a diamond-shape formation. The EOS 5D, released in 2005, takes this 9-point AF system a step further by introducing six more 'invisible' AF points (i.e. not user-selectable) in helping the camera acquire focus faster during subject tracking. Older Canon DSLRs usually have seven-point AF.

For the earlier generation of 45-point AF system, the central column of 1 or 2 sensors (7 in all up to EOS-1Ds Mk II, EOS-1D Mk II N) are cross-type sensors, which offer a high degree of accuracy. The latest announced EOS-1D Mk III and EOS-1Ds Mk III have 19 cross-type sensors for higher accuracy, as well as placing the cross-type sensors to complement the Rule of Thirds.

Naming Scheme

Target Market Segment Typically Common features International Americas Japan
Consumer/Entry-level Pentamirror type viewfinder, lighter and cheaper build than other ranges, APS-C sized sensor on digital models. 3- or 4-digit model number.

E.g. EOS 350D, EOS 300X, EOS 1000D

Rebel (used in North America since 1990)

E.g. EOS Digital Rebel XT, EOS Rebel T2

Kiss (used in Japan since 1993)

E.g. EOS Kiss Digital N, EOS Kiss 7

Advanced amateur/prosumer Higher frame rate and more rugged construction than contemporary "entry-level" models. Partial weather sealing and APS-C sized sensor on digital models. 2-digit model number

E.g. EOS 33V, EOS 40D


E.g. EOS Elan 7N (DSLRs share the same naming scheme as International)


E.g. EOS 7s

Premium Weather sealing and tougher construction. 35mm "Full-frame digital SLR" sensor on digital models. 1-digit model number

E.g. EOS 3, EOS 5, EOS 5D

Same as International, except EOS A2 (EOS 5) Same as International
Professional More rugged/waterproofed build than premium models, larger build with vertical grip, 100% viewfinder field of view, faster performance. APS-H sized sensors on 1D models and 35mm "Full-frame digital SLR" sensors on 1Ds models. model number 1

E.g. EOS-1D Mark II, EOS-1V, EOS-1Ds Mark III

Same as International Same as International

Film cameras

This is a list of the 35 mm and APS Canon EOS models in order of introduction:
Model (US) Model (Europe) Model (Japan) Release date
EOS 650 EOS 650 EOS 650 March 1987
EOS 620 EOS 620 EOS 620 May 1987
EOS 100% EOS 100% EOS 100% October 1988
EOS 850 EOS 850 EOS 850 October 1988
EOS 630 EOS 600 EOS 630 QD April 1989
EOS-1 EOS-1 EOS-1 September 1989
EOS RT EOS RT EOS RT October 1989
EOS 10S EOS 10 EOS 10 QD March 1990
EOS 700 EOS 700 EOS 700 QD March 1990
EOS Rebel/Rebel S EOS 1000F QD EOS 1000 QD October 1990
EOS 10S commemorative kit EOS 10 EOS 10 QD August 1991
EOS Elan EOS 100 EOS 100 QD August 1991
EOS Rebel II/SII EOS 1000FN QD EOS 1000S QD March 1992
EOS A2/A2e EOS 5 EOS 5 QD November 1992
EOS Rebel XS EOS 500 EOS Kiss September 1993
EOS Rebel X - - November 1993
EOS-1N EOS-1N/1N HS/1N DP EOS-1N/1N HS/1N DP November 1994
- EOS 5000 EOS 888 January 1995
EOS-1N RS EOS-1N RS EOS-1N RS March 1995
EOS Elan II/IIe EOS 50/50e EOS 55 September 1995
EOS Rebel G EOS 500N New EOS Kiss September 1996
EOS IX EOS IX EOS IX E October 1996
EOS IX Lite EOS IX 7 EOS IX 50 March 1998
EOS-3 EOS-3 EOS-3 November 1998
- EOS 3000 EOS 88 March 1999
EOS Rebel 2000 EOS 300 EOS Kiss III April 1999
EOS-1v EOS-1v EOS-1v March 2000
EOS Elan 7/7e EOS 30 EOS 7 October 2000
- - EOS Kiss III L November 2001
EOS Rebel XS N EOS 3000N Canon EOS 66 February 2002
EOS Rebel Ti EOS 300V EOS Kiss 5 September 2002
EOS Rebel GII - - March 2003
EOS Rebel K2 EOS 3000V EOS Kiss Lite September 2003
EOS Elan 7N/7NE EOS 30V/33V EOS 7s April 2004
EOS Rebel T2 EOS 300X EOS Kiss 7 September 2004

Digital cameras

Prior to the introduction of the EOS D30 digital SLR, Canon in collaboration with Kodak produced four digital SLRs by modifying the internals of the EOS-1N film SLR. These four digital SLRs had a Canon EOS body and As a result can accept EF lenses, while the image sensor and electronics were designed and built by Kodak. The four cameras were: 
Model Release date
EOS DCS3 July 1995
EOS DCS1 December 1995
EOS D2000/Kodak DCS520 March 1998
EOS D6000/Kodak DCS560 December 1998

The following digital SLRs, starting from the D30, had bodies and sensors completely designed and manufactured by Canon (except for the Canon EOS-1D, which uses a Panasonic sourced CCD sensor).

Unlike most other digital SLR manufacturers, Canon digital SLRs are equipped with a CMOS sensor (with the exception of EOS-1D that uses a CCD sensor). Canon design and manufacture their own CMOS sensors

Canon Digital SLR Cameras


Single lens reflex

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