The Ultimate EOS.
Canon has brought the best of the EOS-1D Series of digital cameras into one phenomenal model: the new flagship of the EOS line, the EOS-1D X. Its full-frame 18.1 Megapixel CMOS sensor and all-new Dual DIGIC 5+ Image Processors deliver high quality image capture at up to 12 fps (14 fps in Super High Speed Mode) and a powerful ISO range of 100 – 51200 (up to 204800 in H2 mode) provides sharp, low-noise images even in the dimmest low-light conditions.
An all-new, 61-Point High-Density Reticular AF and 100,000-pixel RGB Metering Sensor that uses a dedicated DIGIC 4 Image Processor, makes the EOS-1D X reach new levels of focus speed and accuracy delivering advanced tracking even for the most challenging shooting situations.
Taken all together, the EOS-1D X’s improved HD video capture, numerous connectivity options, combination of processing power and durable construction, including shutter durability tested to 400,000 cycles, make it the ultimate EOS.
In response to user requests, Canon has expanded the autofocus versatility of the EOS-1D X DSLR with Firmware Update Ver. 1.1.1. This update greatly enhances the sophisticated 61-point High Density Reticular AF System of the EOS-1D X DSLR. This firmware update adds two important autofocus capabilities: AF point illumination during AI Servo AF and cross-type AF support at f/8.
Information from the Canon USA website.