Nikon SB-900 Speedlight
As a replacement to the SB-800, the SB-900 shares many of the same functions, but also has some innovative additions and improvements. Its automated zoom head has been expanded to cover 17mm to 200mm lenses (in 35mm/FX format), 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.
Note: The SB-900 is only fully compatible with DSLR cameras that support i-TTL operation. With older cameras that use the D-TTL mode, only [A] Auto mode (non-TTL) is available.