The Speedlite 600EX-RT features a wireless multiple flash system using radio wave communication that provides precise control over as many as five groups or fifteen individual flashes at a distance of up to 98.4'. Communicating on 2.4 GHz frequency, it will not be interrupted by physical barriers. It is also very powerful, with a guide number of 197' (60 m) at ISO 100 and a zoom flash head that covers a 20-200mm range. It provides full swivel movement of 180° in both directions. Compatible with the AF frame of all EOS cameras, the Speedlite 600EX-RT even works perfectly with the 61-Point High Density Reticular AF found in the EOS-1D X and the EOS 5D Mark III. It supports all current versions of TTL, including evaluative E-TTL II.
A dot matrix LCD panel and backlit button provide easy visibility and flash functions can be controlled via the camera's menu. A metal hot-shoe and a dust and water-resistant body allow it to be used in adverse conditions, and the included color filter holder and two orange color filters multiply your creative options.
The ST-E3-RT Speedlite Transmitter mounts to your camera's hot shoe and controls up to 15 flash units or 5 flash groups. It can communicate with its flash units up to a distance of 98.4' and from anywhere within a 360º angle. It supports E-TTL II flash, manual flash, stroboscopic and auto external flash metering and offers 8 custom functions and 3 personal functions.