The new 63-zone evaluative metering system (shared with the EOS-1D Mark III) is linked to the AF points for optimum accuracy in a wide range of situations. There’s also 8.5% partial, 2.4% spot, AF-point-linked spot, multi-spot and center-weighted average metering.
2 Powerful DIGIC III Processor
Thanks in part to new dual parallel-processing DIGIC III imaging engines (vs. one DIGIC II in the Mark II), the Mark III can shoot those huge images at five per second in bursts of up to 56 Large/Fine JPEG or 12 RAW. The new processors also provide finer image detail and more natural color, as well as more efficient energy consumption. And 14-bit A/D conversion can recognize four times as many colors/brightness steps as the Mark II’s 12-bit conversion.
3 21.1-Megapixel CMOS
The EOS-1Ds Mark II is formidable at 16.7 megapixels, but the Mark III’s 21.1-megapixel Canon-developed and Canon-manufactured CMOS image sensor raises that by 26%, creating 5632x3750-pixel images that open to around 60 MB in Photoshop. The sensor’s full-frame (36x24mm) size means there’s no crop factor—lenses frame just as they do on a 35mm SLR.
4 45-Point AF
Essentially the same AF system used in the EOS-1D Mark III action camera introduced a few months ago allows the new EOS-1Ds Mark III’s autofocusing to keep up with the 5 fps shooting rate. There are 45 AF points, including 19 high-precision cross-types and 26 Assist AF points. The 19 cross-type points can be divided into groups of 9 inner or 9 outer (plus center point) for quicker manual-point selection.
5 Integrated Cleaning System
Big image sensors seem to collect even more dust than smaller ones, but the Mark III incorporates Canon's EOS Integrated Cleaning System to make sensor dust a thing of the past. A lightweight, infrared-absorption glass cover over the sensor vibrates ultrasonically each time you switch the camera on or off to remove dust. A Dust Delete Data feature maps any dust remaining on the sensor and removes it during postprocessing with the supplied Canon DPP software.
6 Weather-Resistant Body
Especially important to outdoor photographers is the Mark III’s extremely rugged body, with excellent dust- and weather-proofing. A great companion for outdoor work is the new 580EX II Speedlite, which is also weatherproof.
7 ISO Flexibility
ISOs from 100 to 1600 can be set in 1/3-step increments. There are also settings of 50 and 3200.
8 Live-View LCD
Besides being much larger than the Mark II’s LCD monitor (three inches vs. two inches), the Mark III’s monitor provides Live-View capability. In Live-View mode, you can compose using the LCD monitor when you wish (especially useful for odd-angle shooting, close-ups and tripod-mounted work, and when using TS-E tilt/shift lenses), zooming a selected portion of the image 5x or 10x for pinpoint manual focusing. You can also display the image on a computer via USB 2.0 Hi-Speed cable (or wirelessly with the optional new Wireless File Transmitter WFT-E2A) and operate the camera remotely in Live-View mode with the included EOS Utility software.