The camera's 21.1MP, full-frame 35mm-format (24x36mm) CMOS sensor captures image files with incredible image quality and color accuracy, as either JPEG, RAW and RAW+JPEG files. The camera also incorporates Canon's acclaimed DIGIC 4 imaging processor that works in concert with a high-speed DDR-SDRAM buffer to ensure quick performance and fast image processing times. Performance enhancements enabled by the DIGIC 4 processor include an incredibly fast full-resolution frame rate of up to 3.9 fps, improved battery life, noticeably improved image quality at all ISO sensitivities, fast start-up and reaction times, and improved noise suppression at ISO sensitivities ranging from ISO 100 to ISO 6400, plus the camera's sensitivity is further expandable to a range of ISO 50 to ISO 25600.

The Canon EOS 5D Mark II incorporates a high-fidelity (920,000 dot) 3" LCD screen and includes a 'Live View' feature that permits the user to frame their shots on the LCD display, and adds framing functions that are not possible with a traditional SLR viewfinder, including the ability to zoom in and navigate the preview image to ensure proper focus, and a grid overlay to assist in proper composition. The Live View focusing system also enables focus modes such as Quick mode, Live mode and Face Detection Live mode. Furthermore, the Live View Feature enables HD video recording that can capture true HD-quality (1080p) video at a frame rate of 30 fps with Face Detection and sound.

The magnesium-alloy chassis of the EOS 5D Mark II ensures the durability of the camera so users can take it on safari or to a press junket and be assured that the camera can take it. In addition the camera body incorporates extensive dust and weatherproofing features including seals and gaskets where body panels and/or camera controls meet. To further keep the imaging sensor free from dust, Canon's EOS Integrated Cleaning System uses ultrasonic vibrations to shake dust particles off of the sensor's low-pass filter each time you power up (or manually when needed). This ensures that your images will be spot free and reduces time needed for image retouching.

Other professional quality features found on the Canon EOS 5D Mark II include 14-bit A/D conversion, a bright viewfinder (with 98% image coverage), Auto Light Optimizer, Lens Peripheral Illumination Correction, 9-point AF plus 6-point assist AF, 25 Custom Functions with 71 settings, and 5 metering modes (35-Zone EV, 8% Partial Spot, 3.5% Spot, Center-Weighted, and Pre-Flash E-TTL II). Altogether, the Canon EOS 5D Mark II has been designed to serve the needs and interests of serious enthusiasts as well as professional photographers who are in pursuit of the perfect image.