Nikon has unveiled its flagship DSLR camera, the D4s, which sports the same 16.2-megapixel full-frame image sensor as the D4, but how features significantly improved speed across the board and better image processing. Frame rate has been increased to 11 fps, with 30-percent more processing power to enable autofocus and autoexposure on each of those 11 frames. Additionally, Nikon's Expeed 4 image processor combines with the new CMOS imager to allow the D4S to shoot from ISO 50 to a Hi-4 sensitivity of 409,600 (standard maximum: ISO 25,600). Compare this to the D4, which could shoot to just 204,800 (standard maximum: ISO 12,800). Nikon has also upgraded the AF system for both photos and video, highlighted by a new Group AF setting that can track five points simultaneously, making sure that a moving subject stays in focus at all times. Look for the Nikon D4S to carry a price tag of $6,500 when it launches in stores March 6th.