The Nikon D4 DSLR is equipped with a new Nikon FX-format CMOS image sensor (imaging size of 36.0 x 23.9 mm) and EXPEED 3, the latest image-processing engine specifically optimized for digital-SLR cameras, making it the next-generation flagship Nikon digital-SLR camera with the ultimate in versatility and functionality that offers superior image quality rich in detail along with excellent high-speed performance. It has an effective pixel count of 16.2-million pixels and offers superior image quality under a broad range of lighting conditions with its image sensor supporting an incredible range of sensitivities from ISO 50 to ISO 204800.
The new 91K-pixel (approximately 91,000 pixels) RGB sensor supports the Advanced Scene Recognition System, which is able to recognize human faces even when images are framed using the optical viewfinder. In addition, the Advanced Scene Recognition System offers significant improvements in AF, AE, i-TTL flash control and auto white balance (AWB) control accuracy.
The 51 focus point AF system has been improved with faster initiation of autofocusing and the ability to detect and focus on subjects with less lighting. In addition, 11 focus points are fully functional when lenses with a maximum aperture of f/8 are used. All of this means more precise autofocusing when super-telephoto NIKKOR lenses are used with teleconverters (2.0x). The Multi-area Mode Full HD D-movie movie recording function is capable of recording full-HD movies at 30 fps and offers three movie recording formats for selection according to recording conditions or creative intent.
In addition to built-in wired LAN features, the D4 also supports high-speed image transfer via wireless LAN when the new, compact, easy-to-use Wireless Transmitter WT-5 (available separately) is connected to the camera. The D4 is also equipped with a number of new functions that support a more efficient workflow for professional photographers, including one that allows users to add IPTC (International Press Telecommunications Council) information to images.
New Firmware Update; http://support.nikonusa.com/app/answers/detail/a_id/18115
The Nikon D4 is commonly used for Family photos, Landscape/scenery, Low light, Sports/action, Video, Weddings, Wildlife and more.The Nikon D4 is most used by customers who consider themselves to be a Pro photographer among others.The Nikon D4 is popular because customers like the following qualities of the Nikon D4: Easy to use, Fast / accurate auto-focus, Fast shutter speed, Good image quality, High ISO performance and Large clear LCD