ABSTRACT
The electronic flash unit is a simple device. It houses electronic circuits, a capacitor to store energy, and a flash tube. Power from batteries, or sometimes AC household power, is modified by the internal electronic circuits and stored in the capacitor. Many flashes have a pull-out diffuser panel that spreads the light emitted by the flash unit. Flash is often used indoors with a wide-angle lens to spread the light over a larger area. To better light objects at different distances, the full-featured modern flash can zoom the flash head concentrate or expand the beam of the emitted light. Many photographers are not aware that flash mounted in the camera's hot shoe, or even a pop-up flash, controls one or more remote flash units. A Nikon SB-910 set to commander mode and mounted in the hot shoe can control one or several Nikon SB-910's, SB-800's, and other models in any combination when they are set to their remote mode.
