Complete with built-in radio transmission wireless functionality, the Speedlite 600EX-RT sits at the top of Canons on-camera E-TTL / E-TTL II compatible flash lineup with a powerful guide number of 197 at ISO 100 and 200mm. This two-way 2.4 GHz radio system provides added reliability and a range up to 98.4 among up to 5 groups with a total of 15 individual Speedlites. This system also does not need direct line-of-site like traditional optical-based transmission and will work through obstacles.

For added coverage and functionality, the flashs zoom head can reach from 20-200mm, with the option for wide 14mm coverage when the built-in diffusion panel is used. Also, the unit can tilt from -7 to +90° and rotate 180° either left or right for complete bounce capabilities. On the back of the 600EX-RT is a backlit dot-matrix LCD panel that displays the status and allows users to easily access and change settings. Additionally, the flash is durable with a redesigned contact construction and improved dust and water resistant sealing.

Other capabilities of the 600EX-RT include a stroboscopic mode as well as high-speed, first and second curtain sync settings for more control over your images final look. The flash is powered by 4 AA batteries which provide a recycle time of 0.1-5.5 seconds, though it does have a port for an optional external power pack. It comes with a color filter holder with case, a light orange filter, a dark orange filter, a mini stand, and a Speedlite case.