A powerful and versatile flash, the Nikon SB-900 AF Speedlight features a guide number of 111.5′ at ISO 100 and its automated zoom head covers a wide 17mm to 200mm focal length range, and can cover this range in just 1.2 seconds. This flash lets you select from three light distribution patterns: Standard, Center-weighted, and Even. It will also automatically detect if it is connected to a DX or FX format camera, and adjust itself accordingly.
The SB-900 can work as a stand-alone flash, or as part of a wireless group, either in Commander mode or as a slave (remote). The i-TTL system in this flash supports Advanced Wireless Lighting and versatile functions for up to four groups of Speedlights, with 3 remote i-TTL Speedlight groups controlled through the master SB-900. i-TTL Balanced Fill-Flash flash control employs Nikon’s Advanced Data Communication system. This system provides an improved method for the monitor pre-flash and wireless operation that marks an evolution in higher precision over Nikon’s acclaimed D-TTL Balanced Fill-Flash control system, and forms the core of the Creative Lighting System.