In addition to the EOS 5D Mark III, Canon is also announcing the first professional Speedlite on the market with a built-in wireless radio transmitter, the new Speedlite 600EX-RT. The new Canon Speedlite 600EX-RT is the flagship model in the Speedlite line, ideal for wedding portrait and photojournalism. Compatible with all EOS Digital SLRs, this new model eliminates the need for accessory radio slave units and their inherent limitations. Speedlite 600EX-RT features Master-Slave two-way transmission, letting the photographer control the Speedlite settings directly from the "Master" camera.
Radio-based Wireless E-TTL can be performed with up to 15 Speedlite 600EX-RT "slave units", used off-camera up to 98.4 feet (30m) away, and triggered by either a "Master" 600EX-RT on-camera, or the optional new Speedlite Transmitter ST-E3-RT. Used with the EOS 5D Mark III or EOS-1D X, up to five groups of flashes can be completely controlled, independently, off-camera. And, it remains fully compatible with Canon's legacy optical-based Wireless E-TTL technology, for users already committed to existing EOS Speedlites. The Speedlite features enhanced weather-resistant construction - matching that of the EOS-1D X camera body - and a more reliable electrical contact. The flash head zoom range now reaches from 20mm to 200mm.The Speedlite also allows remote shutter release of a single EOS camera, or Linked Shooting (simultaneous firing of up to 15 cameras, when one "Master" camera is fired), and includes gelatin filters and a dedicated filter holder to help photographers match ambient light.
Speedlite Transmitter ST-E3-RT
Canon is also introducing the new Speedlite Transmitter ST-E3-RT. Providing full support of Canon's new radio-based wireless flash technology, the new ST-E3-RT can control up to five groups of flashes, up to 98.4 feet (30m) from the camera. The remote shutter release capability enables photographers to either fire a single camera remotely (by pressing a button on the ST-E3-RT), or to fire up to 15 EOS cameras with Canon's Linked Shooting feature. Making it easy to control and adjust, all of the Speedlite Transmitter features are accessible through the Flash control menu of the EOS-1D X and EOS 5D Mark III cameras.