A direct replacement for the company's previous 1D Mark III model, the Canon EOS-1D Mark IV uses a new CMOS image sensor and dual DIGIC 4 image processors, which together have allowed Canon to offer both an increase in image resolution to 16.1 megapixels, along with a huge step forwards in the camera's ISO sensitivity range which now reaches as high as an expanded ISO 102,400 setting. Adopted from the previous EOS 7D model, there's also a new higher-resolution LCD display with improved reflection / glare resistance in the 1D Mark IV.
The Canon EOS-1D Mk IV also has a significantly uprated autofocus system, and high definition video capability at resolutions up to 1,920 x 1,080 pixels with a jack allowing optional use of an external stereo mic. The 1D Mk IV also supports UDMA Mode 6 CompactFlash cards, adds Canon's Peripheral Illumination Correction technology, debuts a new generation of Canon's Auto Lighting Optimizer function, and quite a bit more besides
The newly published 1D Mk IV white paper can be found in Canon's Digital Learning Center, and comes in at a whopping 123 pages long. Inside, you'll find detailed specifications, summaries of changes from the previous model, and of new and improved features, as well as detailed discussion of the AF system, high ISO performance, HD video capture, new CMOS sensor, improved JPEG workflow, bundled software and well over a dozen other notable features. The EOS-1D Mark IV first-look videos are also found in the Digital Learning Center. Alongside previous videos on the AF system and image quality, there are two new videos covering HD video capture and the camera's controls and custom functions.
For more details on the Mk IV digital SLR beyond what's available from Canon, read our 1D Mk IV preview.