High-end Canon SLR counters Nikon

Among the camera's new features are a higher shooting rate, a new image processing chip, a live display, a more sensitive image sensor and a self-cleaning sensor.

The camera, due in April and expected to cost close to $4,000 without a lens, is geared for photojournalists. Canon does well in the among professionals buying digital SLR cameras--single-lens reflex models that have better image quality, interchangeable lenses and steeper prices--but faces stiff competition from Nikon's D40, D80 and D200 models. The company also faces longtime SLR rivals Pentax, Olympus and Fujifilm and newcomers Panasonic, Sony and Samsung.

The 10.1-megapixel 1D Mark III can shoot 10 frames per second, a notch up from the 8.5 per second of Canon's preceding model, the 8.2-megapixel 1D Mark II N. It can shoot a burst of as many as 30 raw images--those pulled directly off the sensor without camera processing--or 110 JPEGs.

That speed and duration is aimed squarely at the photojournalists who gravitate toward this line--those whose paycheck depends on successfully getting the shot of the sprinter crossing the finish line.

Canon also unveiled new PowerShot cameras for consumers, including the SD750 and SD1000, the vertically oriented TX1 and the A560 and A570 IS.

The EOS-1D Mark III also is the first Canon SLR to sport the new Digic III image processing chip that debuted in point-and-shoots last year. To cope with the high frame rate, though, the 1D Mark III has two Digic III chips. The chips process images 50 percent faster than the Digic II and cut down so-called image noise in darker areas, Canon said. And the new chips' horsepower lets the camera employ 14 bits of data per color, up from 12 bits from earlier models, which means finer tonal distinctions such as the subtle shades of a white wedding dress in the sun.

Another major change is a redesigned and more sensitive image sensor, the heart of the camera. Canon says it's the company's most sensitive yet, with a "highly usable" ISO speed rating up to 6400. High ISO settings--as long as they don't cripple photos with inordinate image noise--are useful for capturing fast-moving subjects or those in low-light conditions. The camera also is Canon's first with an ISO 50 setting for higher-quality images when lighting permits.

The sensor has new microlenses and packs pixels more efficiently, Canon said, a key part of the effort to minimize image noise, such as off-color speckles, by maximizing the sensor area devoted to actually gathering light. As with the 1D Mark II, the sensor is the APS-H size that shrinks the field of view by a factor of 1.3 compared with traditional 35mm film SLRs. That means a 50mm lens on a Mark III has the field of view of a 65mm lens on a traditional film SLR. (The APS-H size is right between the APS-C sensor, which has a 1.6 crop factor and is used in Canon Rebel XTi and 30D SLRs, and the full-frame sensor, which matches 35mm film and is used in the 5D and 1Ds Mark II.)

The 1D Mark III also is the first Canon SLR to include the live preview feature that first arrived on Olympus SLRs. Point-and-shoot camera users are typically accustomed to composing their shots using the camera's LCD--indeed, most new cameras have no other way to do so--but most SLRs can only show the image after it's been taken. Canon's Live View mode lets photographers compose using the camera's 3-inch LCD if they desire, and the camera can send the preview image to a computer connected with USB or wirelessly with the new WFT-E2A transmitter.

The transmitter also can send images for remote storage. And the camera can store data locally with Compact Flash or SDHC memory cards.

The 1D Mark III also includes a sensor cleaning technology that shakes the sensor when the camera is turned on or off to dislodge dust specks that often mar SLR pictures. Sensor cleaning first showed up in Canon SLRs with the Rebel XTi introduced in 2006.

Also new is a 45-point autofocus system; a lithium-ion battery that lasts 2,200 shots compared with 1,200 for the 1D Mark II N's nickel metal hydride battery; a security kit to verify the authenticity of images and accompanying descriptive metadata; a shutter rated to last 300,000 exposures; and a new "sraw" image file format. Canon said sraw has half the file size and a quarter the resolution of conventional raw images.

Canon also announced a revamped high-end L series wide-angle zoom lens with a focal length range of 16-35mm and a relatively high lens speed of f/2.8. The new model has better image quality around the edges of the frame, Canon said.

In addition, the Japanese company announced the 580EX II flash, which is sealed against moisture and dust and has a more durable attachment mechanism than the earlier 580EX.