Sporting an 8.2 megapixel CMOS sensor (twice the resolution of the original EOS-1D), the Canon EOS-1D Mark II is capable of capturing 8 megapixel JPEG images at 8.5 frames per second in continuous bursts of 40 frames, or RAW images in continuous bursts of up to 20 frames. With its DiG!C II image processor, the Canon can process large files quickly, with improved colour rendering and detail. The EOS-1D Mark II sports a redesigned flash metering system that retains compatibility with Canon's EX-series Speedlites. The EOS-1D Mark II captures images well in low-light conditions with less noise; it has good auto white balance control, user-set white balance compensation and many other features. The camera tags images with EXIF 2.21-compatible metadata, including Adobe Systems 1998 RGB colour space profiles, so users don't have to tweak colour space manually in Photoshop.

The EOS-1D Mark II's has a shutter that's been durability-tested to 200,000 exposures. The shutter operates at speeds from 30 seconds to 1/8000 of a second, and has a lag time of just 55ms (adjustable to 40ms). The lens mount is stainless steel and is compatible with all Canon EF, TS-E and MP-E lenses.

The camera accepts CompactFlash Type I and Type II cards as well as Microdrives; it also sports a second card slot that's compatible with SD cards. Settings can even be customised on the camera, saved onto a card and then loaded onto another camera intact.

Digital photographers frustrated by slow interfaces on their existing cameras will be happy to know that the EOS-1D Mark II includes both USB 2.0 and FireWire interfaces, to help images download that much faster. The EOS-1D Mark II supports Picture Transfer Protocol (PTP), so additional drivers aren't required to enable it to talk with a Windows XP or Mac OS X system.

The camera uses the same NP-E3 NiMH power pack seen on the EOS-1D and 1Ds models. According to Canon, the NP-E3 is good for about 1200 shots per charge at normal operating temperatures.