Nikon 25446B D90 User's Manual - Page 254

❚❚ CLS-Compatible Flash Units The D90 can be used with the following CLS-compatible flash units: the SB-900, SB-800, SB-600, SB-400, SB-R200, and SU-800. The SB-900, SB-800, SB-600, SB-400, and SB-R200 The principal features of these flash units are listed below. Flash unit Feature SB-900 1 SB-800 SB-600 SB-400 SB-R200 2 Guide No. 3 ISO 100 ISO 200 34/111 48/157 38/125 53/175 30/98 42/138 21/69 30/98 10/32 14/49 Auto power zoom (mm) 17-200 24-105 24-85 -4 -5 Wide panel (mm) 12, 14, 17 14, 17 14 - - Head rotation 7 ° down, 90 ° up, 180 ° left/right 7 ° down, 90 ° up, 180 ° left, 90 ° right 90 ° up, 180 ° left, 90 ° right 90 ° up 60 ° down (toward lens light axis), 45 ° up (away from light axis) 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 with built-in flash in commander mode or using optional SB-900, 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. 4 27 mm zoom coverage. 5 24 mm zoom coverage. 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. The SU-800 itself is not equipped with a flash. D Use Only Nikon Flash Accessories Use only Nikon flash units. Negative voltages or voltages over 250 V applied to the accessory shoe could not only prevent normal operation, but damage the sync circuitry of the camera or flash. Before using a Nikon flash unit not listed in this section, contact a Nikon-authorized service representative for more information. A Guide Number To calculate the range of the flash at full power, divide the Guide Number by the aperture. For n 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). 234