AThe 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. Refer to the documentation provided with the flash unit for details.

AGuide Number

To calculate the range of the flash at full power, divide the Guide Number by the aperture. If, for example, the flash unit has a Guide Number of 34 m or 111 ft (ISO 100, 20 °C/68 °F); its range at an aperture of f/5.6 is 34÷5.6 or about 6.1 meters (or in feet, 111÷5.6=approximately 19 ft 10 in.). For each twofold increase in ISO sensitivity, multiply the Guide Number by the square root of two (approximately 1.4).

300Technical Notes