When it comes to shooting interior photos, there are numerous advantages to having an off-camera flash, and I will address some of these benefits and techniques in a later post. First, I want to take a minute to outline the different ways you can actually get your flash off of your camera while continuing to sync it to the shutter.
1) The “PC Sync Cable” – One of the more archaic methods of syncing your camera and flash is by running a cable between them. Not all camera bodies or flashes have a PC outlet, but this problem can be overcome through the use of a safe-sync adapter or a PC sync adapter. The cables are generally inexpensive, but can sometimes be hard to find. Furthermore, since many cameras and flashes have custom-sized, proprietary outlets you need at find the exact cable for your needs. Also note that the “PC” is a term often associated with the phrase “personal computer,” but in this case it stands for “Prontor-Compur” and derives from a brand of shutter.
2) The “Off-Camera Shoe Cord” – Similar to the PC Sync Cable, this cord also physically connects your flash to your camera. The advantage here though is that you can continue to use the TTL (Through the Lens) mode on your flash. Essentially, this allows your flash and camera to communicate so that an accurate amount of light is produced by your flash in accordance to your camera settings. This product works without the need of PC outlets, instead using your camera’s hot-shoe, but each camera will require a custom cord in accordance with its make/brand.
3) The “Infrared Transmitter” – With infrared technology you have three choices for setup:
a) Flash (master) to flash(es) (slaves)
b) Infrared transmitter to flash(es)
c) Camera to flash(es) – In order for your camera to directly communicate with a flash it needs to have the infrared transmitter built in.
The disadvantage here is that the infrared signals have a maximum range of around 30-50 feet depending on your location, and cannot communicate very well around objects. TTL modes can be used with infrared technology.
4) The “Radio Transceiver” – Radio transceivers are by far the most flexible in usage, as they communicate well in complex environments and have a range of up to 1600 feet. One transceiver is affixed to the camera’s hot shoe (the transmitter), and one is required for each flash used (the receivers). You cannot use TTL mode with radio transceivers. See Pocket Wizard for more details.
For those eager to learn more about off-camera lighting techniques, please visit one of my favorite photography blogs: Strobist.