Nikon Creative Lighting System (CLS): a lighting system that enables flash photography functions listed below with improved communication between Nikon Speedlights and cameras
i-TTL flash control/Advanced Wireless Lighting/Modeling flash/ FV lock/Flash (LED Light) Color Information Communication/ Auto FP high-speed sync
Guide number (GN): the amount of light generated by a flash unit; GN = flash-to-subject distance (mƁorƁft) × aperture f-number (ISO 100)
Effective flash output distance: flash-to-subject distance with correctly adjusted flash output
Effective flash output distance range: range of effective flash output distance
Flash exposure compensation: intentional flash output change to obtain the desired subject brightness
i-TTL flash control: flash control mode in which the Speedlight fires monitor pre-flashes and the camera measures the reflected light and controls the Speedlight flash output
Monitor pre-flashes:a series of flashes emitted for a very short time before the actual firing that enables the camera to measure the light reflected on a subject
