The AF system in Canon’s EOS cameras has advanced from being only capable of establishing focus automatically on the subject, to being able to track and predict subject movements as well through AI Servo AF. At the same time, Canon has also been putting in aggressive efforts to shift from film to digital photography by introducing cutting-edge technologies ahead of other competitors, and the same can be said about the development of new lens technologies. In the second article of the series, we will look at the dramatic evolution of the EOS system.

Even the professional photographers who originally did not believe in the capabilities of the AF of EOS cameras started to make use of the feature. The advent of the EOS system has rendered the fixed focus technique obsolete.

 

Changing the way professional photographers shoot

Fixed focus is a technique where focus is established on a fixed point where the subject is expected to appear. The photographer then releases the shutter when the subject reaches the anticipated point. Before autofocusing (AF) was developed, photographers used to employ this technique to establish focus on their subjects. However, shots that were captured using this method varied little in character. Meanwhile, for scenes where it is difficult to predict the movement of the subject, such as soccer and rugby games, professional photographers had to shift the focus manually using MF, but there were limitations to how precisely the main subject could be captured with MF, especially for sports with various players moving rapidly in and out of the composition at the same time.

Lavishly equipped with the latest technologies, Canon's AF system is reliable for capturing moving subjects. The number of AF points on EOS cameras has increased from 3 at first to 5, 7, 11, 45. The latest models such as the EOS 5D Mark IV and the EOS-1D X Mark II carry as much as 61 AF points .

 

The introduction of the AI Servo AF feature on the EOS-1 (released in 1989) revolutionised sports photography. Unlike the conventional shooting style which required taking continuous shots after establishing AF in the first shot, AI Servo AF is able to track the vigorous movements of the subject and maintain focus with AF by employing a predictive focusing algorithm that is capable of maintaining focus on a moving subject. This advancement in the AF system on EOS cameras changed the way professional photographers shot, and enabled them to produce images with a stronger impact.

The skill level of sports players and athletes progresses with time, thus it is necessary to ensure the reliability of the AF which professional photographers place enormous trust on. For this reason, Canon focused on the development of AF, equipping it lavishly with technologies that had been cutting-edge at that time, such as a larger number of AF points and eye-controlled AF where users could select an AF point by looking at it through the EVF.

 

Rebirth of the EOS as a digital camera system

The 1990s saw a shift from film cameras to digital cameras. Following Kodak’s release of the DCS100, the world’s first digital SLR (DSLR) camera, in 1991, all the SLR camera manufacturers entered the digital market at the same time. Canon also released a series of models that had been developed in collaboration with Kodak, including the EOS DCS 3 and EOS DCS 1. However, the digital processing unit that was added to the lower part of the camera body was very bulky. In terms of looks, those cameras were a far cry from the DSLR cameras of today.

 

 

The camera that became the prototype for today's DSLR cameras was the EOS D30 (released in 2000). Equipped with a CMOS sensor with a resolution of approximately 3.25 megapixels and an LCD monitor, the EOS D30 made its debut in Japan at an astonishing price of 358,000 yen (approx. USD 3200). This was much lower than the average price of DSLR cameras at that time, which hovered around 2 million yen (approx. USD 18,000).

This adoption of a CMOS sensor was revolutionary, occurring at a time when most cameras generally used CCD image sensors. Ever since, Canon has been developing and producing its own CMOS sensors, and has become the top manufacturer for built-in CMOS sensors of digital cameras. Furthermore, the EOS D30 was also the first camera to come with an image processor, a unit for processing digital images. Later named “DIGIC”, the image processor continues to evolve today. DIGIC is the fruit of Canon’s technological development toward the digital age of cameras which started around 1993, and forms the heart of a digital camera system.

 

EOS constantly rewrites the rules for digital cameras, and its rebirth as a digital SLR camera system was just the beginning. Developers at Canon create hypothetical designs of products that they would likely be using in several years’ time, and develop technologies based on the designs. This is to ensure that proposals that are received from the product planning team can be materialised with the technologies they have developed. Staying a step ahead of the future – that is the root of Canon’s technology.

 

EF lens technology—widening the potential of photographic expression

The scope of photographic expression possible with the EOS system would not have been possible with just the technology in the camera body alone—the technology used in EF lenses is just as important. For instance, Canon was the first in the world to adopt an ultrasonic motor, the USM, in EF lenses as a built-in actuator for driving AF. To ensure pleasant AF on a wide range of lenses that vary in size and weight, it is best to have an optimal motor for each lens. The same goes for the Image Stabilizer (IS) feature – Canon unhesitatingly chose an in-lens stabiliser system so that camera shake correction can be optimised for each lens.

 

EF75-300mm f/4-5.6 IS USM (Released in 1995)
This was the first interchangeable lens for 35mm format SLR cameras to be equipped with the Image Stabilizer (IS) feature. The system detects camera shake using vibration gyros, and moves the stabilising optical components to correct it, providing an IS effect that is equivalent to approximately two shutter speed stops.

 

Canon’s development of lens technologies is not limited to that for the AF drive mechanism. Previously thought to be an impossible task, Canon succeeded in adopting an artificial fluorite lens in 1969 that was capable of delivering vivid images and detailed depictions. At the same time, aggressive efforts were also made to develop other special lenses to enhance the image quality, such as aspherical lenses with an ideal curved surface for converging light to a single point, as well as low-refraction and low-dispersion UD lenses.

There was a tremendous increase in the range of EF lenses starting from around 2000, and many of the additions to the line-up from back then can still be found in the market today in 2017. Many of the EF lenses employ Subwavelength Structure Coating (SWC), which is a special coating technology that defies the common perception about lens surface coatings.

 

EF24mm f/1.4L II USM (Released in 2008)
The first lens to be equipped with the SWC, which is highly capable of suppressing the occurrence of light reflection during the shoot. Lenses that are labelled “II” are packed with the latest technologies.

 

Released in 2008, the large aperture, wide-angle EF24mm f/1.4L II USM was the first lens to be equipped with the SWC technology. Flare and ghosting are minimised by arraying a large number of wedge-shaped nanostructures on the lens surface to change the refractive index. This is yet another example of Canon’s technology that breaks away from conventional thinking and opens up a new frontier in photography.

 

EOS has come a very long way since the days of the EOS 650. For more about the very beginnings of EOS, read:
Celebrating 30 Years of EOS (1): The Very First EOS Camera, EOS 650

To learn about the history and milestones in EF lens technology, check out:
[Part 1] The Dawn Era – Birth of the Fully Electronic Mount
[Part 2] The Growth Era – Advent of the Digital Age
[Part 3] The Transition and Enhancement Era – Lenses for High-resolution Cameras
 

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