The FreeWave Captain Wireless TTL Flash Trigger and Remote TTL Shutter Release System for Nikon SLRs from Vello is a multi-purpose 2.4 GHz, 4-channel digital i-TTL radio system that gives wireless freedom from a PC cord plus the convenience of accurate exposures through wireless communication with your camera's i-TTL flash technology. Imagine the near impossibility of running 300' lengths of PC cord to shoot outdoors, then imagine the wireless freedom of remote triggered, camera control with auto exposure in a radius up to 300'. Using 2 shoe mount i-TTL flashes and an assistant you'd have enough mobility to light groups, demos, shows, portraits and events on location, on-the-fly. And the benefits aren't limited to flash photography either. You can also use the receiver with the included camera cord and handhold the transmitter to wirelessly trigger your camera in single shot, continuous shot, bulb, and timer modes. This is of paramount importance in situations where a subject, such as wildlife, may be difficult to approach. Additionally, the wireless function of the device reduces the potential of camera shake when doing macro, close-up, and long exposure photography. The Captain system can also be combined with the non-TTL FreeWave Fusion Basic system, and additional FreeWave Fusion Basic receivers can be integrated into the Captain system. The Vello FreeWave Wireless TTL Captain's High Speed Sync and Second Curtain Sync functions create easy to control lighting effects and other creative options such as stop-action shooting and a wide degree of background or ambient light control.