Technology Used in Digital SLR Cameras

Since Canon was founded, the company has sought to produce the ultimate SLR camera. The company leads the world with its innovative products that realize high-quality images using groundbreaking technologies such as proprietary lenses, CMOS sensors and image processors.

Large Size CMOS Sensor

High-Resolution, High-Sensitivity, Low-Noise Image Sensor

35 mm Full-Frame CMOS Sensor

The CMOS sensor is one of the key components of a digital SLR camera. Canon conducts development and production of CMOS sensors using proprietary technologies. Canon currently uses two different sizes of CMOS sensor: 35 mm full-frame and APS-C.

Canon's CMOS sensors feature large size and high resolution*1 (Up to approximately 22.3 million pixels with a 35 mm full-frame CMOS sensor), excellent sensitivity (low noise), and a wide dynamic range. Featuring sixteen-channel signal reading, as well as compatibility with high-speed continuous shooting of approximately 14 frames per second and full HD movies supported by DIGIC, Canon's CMOS sensors facilitate new levels of still photo and movie expression that far surpass those of film cameras.

  • *1
    The effective pixels of CMOS sensors are as follows.
Sensor size Imaging screen size Installed products Effective pixels
35 mm full-frame Approx. 36 x 24 mm EOS-1D X Approx. 18.1 million
EOS 5D Mark III Approx. 22.3 million
EOS 5D Mark II Approx. 21.1 million
Approx. 35.8 x 23.9 mm EOS 6D Approx. 20.2 million
APS-C size Approx. 22.3 x 14.9 mm EOS 7D / EOS 60D / EOS Kiss X7i / EOS Kiss
X6i / EOS Kiss X7 / EOS Kiss X5 / EOS M
Approx. 18.0 million
Approx. 22.0 x 14.7 mm EOS Kiss X50 Approx. 12.2 million

Subject Sensing Technology

Realization of Comfortable and Speedy Shooting Using a System Approaching Eyesight

New Area Autofocus System

Area AF Sensor

The autofocus (AF) technology of Canon's EOS series of SLR cameras debuted in 1987, making an impact on the market with its speed and ease of use. Since that time, Canon has continued to develop and evolve AF technology into a digital camera legacy: from its initial AF with a single focus point at the center of the viewfinder to 3-point AF in 1990, 5-point AF in 1992, 45-point AF in 1998 and 61-point Area AF in 2012.

61-Point High-Density Reticle AF

illust: Array of Area AF Sensor Focusing Points

The 45-point Area Autofocus, a standard feature in SLR cameras for professional photographers, has now evolved to 61-point Area Autofocus. The dense array of 61 focus points in the AF frame measures the distance from the subject with pinpoint accuracy through 5 dual-cross- type points for f/2.8 and f/5.6 lenses or 41 cross- type points for f/4 lenses. This evolution is now available with the EOS-1D X and EOS 5D Mark III flagship models.

  • *
    Peripheral focus points may not be available with some lenses.
  • *
    The color representation in the AF frame diagramed above is presented for illustrative purposes only.
    Actual finder images may differ.

63-Zone Dual-Layer Metering Sensor

Conceptual View of 63-zone Dual-layer Metering

The exposure of the subject is determined by the metering sensor. Canon has developed a new 63-zone Dual-layer Metering Sensor with a dual-layer photo sensor. The first layer measures blue-green light and the second layer measures green-red light. By providing functionality for individually measuring the intensity of red and blue wavelengths of RGB primary colors (color information), this automatically and accurately corrects exposure errors caused by the type of light source. This reflects the actual color of the subject and the changing color information of the subject under artificial light, etc. in exposure to complement the camera's exposure characteristics. This eliminates subtle variations in exposure caused by color. The subject area is also detected based on autofocus information, and stable exposure with emphasis placed on the main subject is achieved through a metering algorithm utilized in computing evaluation metering.

Hybrid CMOS AF

New AF System for High-Speed, High-Precision Focus

Canon has developed 'Hybrid CMOS AF', an advanced autofocus technology to enhance the focusing speed for Live View photography and movie shooting.Hybrid CMOS AF is a combination of the phase-difference method for faster focusing and the contrast method for higher accuracy. The picture element embedded in the CMOS sensor (focal plane) designed for phase-difference AF quickly measures the subject distance, then the contrast AF focuses with extreme accuracy. This realizes much faster and more precise focusing than the AF systems of former models.

illust: Digital camera AF method *illustration of the concept.

Phase-Difference AF

Principles of Phase Difference AF Method

The phase-difference AF method works by dividing the incoming subject image that passes through the photographic lens into two images and then detecting the difference in the focus point position between the two images. The original image is split into two images with two secondary microlens arrays in the AF sensor unit. Two line sensors measure each focus point.

The lens moves forward or backward depending on whether the focal point is in front of the subject (closer to the camera), or behind the subject (farther away from the camera). Because the camera can immediately figure out the direction and amount to move the lens, phase-difference AF can focus very quickly.

Contrast AF

Because the contrast is highest when the image is in correct focus, the camera analyzes the contrast information from the image on the imaging sensor and moves the lens to the position that gives the maximum contrast value.The drawback with contrast AF is that the lens must traverse the full focusing range for finding the peak contrast location. This requires more time to reach focus, but results in higher focus accuracy. Contrast AF method is commonly employed on most video cameras, TV cameras, and compact digital cameras.

[Front focus]

[Back focus]


Principles of Contrast AF Method

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