Canon CMOS Sensor and DIGIC III

What a Difference a Frame Makes
Inside the Canon CMOS Image Sensor
CMOS and DIGIC III: A One-Two Punch

What a Difference a Frame Makes
In a crowded and increasingly competitive market for digital SLR cameras, consumers sometimes feel as if all cameras are created equal. Faced with a choice between two 10-megapixel cameras with similar lens kits and memory cards, they'll generally pick the lower price. But there are other factors to consider.

For example, very few digital SLR cameras are built with a 35mm full-frame image sensor. What does that mean? The image sensor is the device that converts visual images into electric signals. Most digital camera manufacturers build these sensors at sizes smaller than full frame in an effort to keep prices down. However, if a photographer tries to use a 35mm camera lens with the smaller image sensor, the edge of the image will be cropped off. In other words, any lens you attach acts like more of a telephoto lens than its marked focal length would tend to indicate.

A full-frame image sensor, on the other hand, is the same size as a 35mm negative. It gives photographers the freedom to use virtually any of their lenses with a digital SLR camera the way they were designed to be used. But that's not the only advantage of full-frame image sensors—they also offer greater detail and better overall image quality.

Inside the Canon CMOS Image Sensor
The Canon sensor 35mm full-frame sensor CMOS image, available on the EOS 5D and EOS-1Ds Mark III, gives photographers more freedom in lens usage and a broader range of creative possibilities because of its large size. Canon's newest full-frame CMOS sensor in the top-of-the-line EOS-1Ds Mark III offers 21.1-megapixels and a recording area of 36x24mm—the same size as the full-frame 35mm film format.

This powerful sensor improves image quality in several tangible ways:

  • Better image resolution. Higher resolution means more accurate rendering of details, even when images are enlarged. Canon's CMOS sensor enables you to take pictures with image quality that's fine enough for 10x12 inch prints—or even posters.
  • Minimized blowout and black crush. Ever seen a picture with completely white spots in the brightest areas? Or completely black spots in the shadowy sections? That's what happens when the illumination of the shot is higher or lower than the sensor can record—but the Canon CMOS sensor has a wide dynamic range to minimize most instances of blowout and black crush for a more realistic overall appearance.
  • Precise gradation. The CMOS sensor also uses its dynamic range to capture all the nuances of color and shading that can be found in nature. As a result, your pictures are free of unnatural jumps from one shade to the next.
  • Accurate color reproduction. Canon CMOS sensors supply ample color information to a powerful imaging engine, resulting in more faithful renderings of delicate colors and shading.
  • Reduced noise and false color. Noisy images have an unattractive grainy quality, and false color is a common problem for the single-plate sensors used in digital SLR cameras. Canon CMOS sensors minimize these problems—without requiring you to spend hours adjusting images on a computer.
  • Better background blur. Blurring your background can make your image subject "pop" for an appealing overall effect. But most digital SLR cameras with smaller imaging sensors can't blur backgrounds as effectively as 35mm SLR cameras. The Canon full-frame CMOS sensor, when used with large-diameter EF lenses, helps you master this advanced photographic technique.

CMOS and DIGIC III: A One-Two Punch
As we've seen, the Canon CMOS sensor accurately captures huge volumes of visual data to lay the foundation for breathtaking photos. Where does the data go from there? To the DIGIC III Image Processor—a next-generation processor that ensures high levels of performance as you shoot one detailed shot after another.

As the latest development in Canon's proprietary DIGIC processor line, the DIGIC III offers significant speed enhancements in start-up time, auto focus, and shutter response, as well as extended battery life. This processor is entirely designed by Canon, and unlike general-purpose processors, it's designed to work strictly in a still camera environment. It's a significantly more powerful processor than previous versions, and it’s able to perform more calculations and tasks and do them faster than ever. As JPEG images are processed, for example, the DIGIC III processor is even better-suited to reduce digital "noise" in your finished images, without simply blurring actual subject details.

To provide the fastest possible bridge between image capture and image recording, the Canon EOS-1Ds Mark III and EOS-1D Mark III digital SLR cameras feature dual DIGIC III image processors. By performing parallel processing—a feat that is common among computers but rare in digital cameras—the DIGIC III processors safeguard image quality while moving data at previously unheard-of speeds. A camera that uses dual DIGIC III processors can process images 1.5x faster than a camera using a single DIGIC II processor.

So, what's the overall effect of combining Canon's full-frame CMOS sensors with DIGIC III? You start with a large image sensor and the freedom to choose virtually any lens; you add in the ability to record up to 21.1 megapixels of resolution; and you process all of this visual information at a blinding speed, while preserving image quality.