Nikon D3100 D3100 User's Manual - Page 189

The Nikon Creative Lighting System (CLS) Nikon's advanced Creative Lighting System (CLS) offers improved communication between the camera and compatible flash units for improved flash photography. ❚❚ CLS-Compatible Flash Units The camera can be used with the following CLS-compatible flash units: • The SB-900, SB-800, SB-600, SB-400, and SB-R200: Flash unit Feature SB-900 1 SB-800 SB-600 SB-400 SB-R200 2 Guide ISO 100 34/111 38/125 30/98 21/69 10/33 No. 3 ISO 200 48/157 53/174 42/138 30/98 14/46 1 If a color filter is attached to the SB-900 when AUTO or N (flash) is selected for white balance, the camera will automatically detect the filter and adjust white balance appropriately. 2 Controlled remotely using optional SB-900 or SB-800 flash unit or SU-800 wireless Speedlight commander. 3 m/ft., 20 °C (68 °F), SB-900, SB-800 and SB-600 at 35 mm zoom head position; SB-900 with standard illumination. • The SU-800 wireless speedlight commander: When mounted on a CLS-compatible camera, the SU-800 can be used as a commander for remote SB-900, SB-800, SB-600, or SB-R200 flash units in up to three groups. The SU-800 itself is not equipped with a flash. A Guide Number To calculate the range of the flash at full power, divide the Guide Number by the aperture. For example, at ISO 100 the SB-800 has a Guide Number of 38 m or 125 ft. (35 mm zoom head position); its range at an aperture of f/5.6 is 38÷5.6 or about 6.8 meters (or in feet, 125÷5.6=approximately 23 ft. 7 in.). For each twofold increase in ISO sensitivity, multiply the Guide Number by the square root of two (approximately 1.4). n 173