Multi-step auto zoom covers wide 17-200mm zoom range (24-105mm：SB-800)
Three illumination patterns (standard, center-weighted and even) are available to match each shooting environment

Automatically detects Nikon FX and Nikon DX formats and selects suitable light distribution
Improved booster circuit for high-speed recycle time: Recycle time using four AA-size batteries is almost equal to the SB-800 with five AA-size batteries
New AF-Assist illumination covers a wide 20-105 mm focal range compatible with the new Multi-CAM3500 FX/DX AF sensor
Firmware update via Nikon D3 and D700 is possible (world's first*)
Thermal Cut-out function limits the number of flashes to avoid deterioration of light emitting parts caused by continuous flash firing
Automatically detects color filters (fluorescent or incandescent), enabling camera to control color temperature according to filter information from SB-900
Optional Water Guard WG-AS1 (for D3), WG-AS2 (for D300), and WG-AS3 (for D700) is useful for protecting the camera's hot shoe contact when the SB-900 is mounted on these Nikon digital SLR cameras

Ready light
 
 The SB-900 is fully recycled: Rear ready-light lights up and front light blinks Insufficient light for correct exposure (in i-TTL, Auto Aperture flash, Non-TTL Auto flash, or Distance-priority manual flash operations): ready-lights and front lights blink after shooting 

 
Flash duration
 
 Approx. 1/880 sec. at full output

 
Mounting foot lock lever
 
 Provides secure attachment of SB-900 to camera's accessory shoe using locking plate and mount pin to prevent accidental detachment.

 
Dimensions (W x H x D)
 
 Approx. 78.0 x146.0 x 118.5 mm (3.0 x 5.7 x 4.7 in.)

 
Weight (without batteries)
 
 Approx. 415 g (14.6 oz.)

 
Supplied accessories
 
 Speedlight Stand AS-21, Nikon Diffusion Dome SW-13H, Color Filter Set SJ-900, Color Filter Holder SZ-2, Soft Case SS-900