Triggering an off-camera flash unit helps illuminate a subject for a sculptural effect. Flash accessories, such as cords, transmitters and wireless sensors in flash units, achieve the off-camera flash effect. These flash accessories offer an economical and often lightweight and portable alternative to expensive studio lighting systems.
Hot Shoe Extension Cord
A hot shoe extension cord connects the camera's hot shoe mount and flash unit's mounting foot. The extension cord allows the photographer to hold the external flash unit in one hand and the camera in the other hand. If the photographer and the subject are mobile, such as at a wedding shoot, this light source can adapt to changes in the distance between the camera and subject. Attaching the flash unit to a flash bracket makes the device easier to hold and extends the distance from the camera body.
PC Sync Cord
A PC sync cord synchronizes the shutter with the off-camera flash unit. The initials "PC" refer to "Prontor-Compur" connection, a standard electrical connector. This connection requires a PC terminal or socket on the camera and the flash unit. For example, the Canon 580 EX II flash unit contains this PC terminal. If the camera lacks a PC sync port, an adaptor with a PC port inserts on the camera body's hot shoe to provide the cable connection. A PC sync cord is available in longer lengths than a hot shoe extension cord. The PC sync cord also synchronizes with strobe lights. Working with a PC sync cord is better suited for stationery subjects in a studio setting.
Transmitter and Receiver
A transmitter and receiver can trigger off-camera external flash units without wires or cables. For example, the Cactus Wireless Flash Trigger system includes a transmitter for the camera's hot shoe and a receiver for the slave flash unit. Pressing the camera shutter activates the transmitter to emit the radio signal that fires the wireless slave unit. Adding more flash units, each with a receiver set to the same channel, allows more flash units to work together. For example, two or more flash units can set to different lighting ratios.
Built-In Wireless Slave
Cameras and flash units with a wireless slave feature can also fire off-camera. For example, the Canon EOS 60D camera has a built-in flash that triggers the off-camera Canon Speedlite 580 EX II flash unit. Instead of using a radio frequency, this system uses the light fired from the built-in flash to communicate with the wireless sensor on the external flash unit. The built-in flash can set to a minimum output to avoid interfering with the slave unit's flash output.
Portable Flash Unit on a Multi-Clamp Adaptor
A multi-clamp fitted with a hot shoe mount also provides off-camera flash photography. This clamp attaches over a light stand and allows the light to position higher. The external flash unit's mounting foot inserts into the hot shoe mount for a stable, yet flexible position. Communication between the camera and the flash unit can work with cords, wires or wireless transmitters. An advantage is the flexibility to move the flash unit at varying distances from the stationary subject. The disadvantage is the lighting stand is hard to move if the subject moves.
Portable SLR Flash Package
A portable SLR flash package adapts well for on-location work. Adding a battery pack allows portability without the need for an electrical outlet. A custom package, for example, can include hot shoe to PC adaptor, a PC sync cord, an external flash unit, a battery-operated strobe with a rechargeable battery pack, two light stands and an umbrella bracket. The PC sync cord connects the external flash unit to the hot shoe to PC adaptor on top of the camera. The lights stands support the external flash unit with the umbrella bracket and the more powerful slave unit with the battery pack. The external flash unit fires and wirelessly triggers the slave unit's sensor. An example of a slave unit is the JTL Mobilight, suitable for a main light, fill light or back light.
Tags: flash unit, external flash, external flash unit, flash units, slave unit, sync cord
