600EX RT II
The Canon 600EX RT II is a powerful on-camera E-TTL / E-TTL II compatible flash featuring built-in radio transmission wireless functionality, and a powerful guide number of 197' at ISO 100 and 200mm. This model offers improved continuous flash performance by 1.1-1.5x, or up to 2.0x with an optional battery pack, simplifies the menu system for faster operation, and includes a specially designed bounce adapter, a hard colour filter, and an updated soft case.
The two-way 2.4 GHz radio system provides added reliability and a range up to 30 metres among up to 5 groups with a total of 15 individual speedlights. It does not require line-of-site like the traditional optical-based transmission, and will work even through obstacles. Optical transmission is available however, in addition to radio transmission, offering you a choice of control.
The flash's zoom head provides coverage from 20-200mm, and 14mm when the built-in diffusion panel is used. Tilt from -7 to +90° and rotate 180° either left or right for complete bounce capabilities. On the back of the flash is a backlit dot-matrix LCD panel that displays the status and makes accessing and changing settings simple. A redesigned contact construction and improved dust and water resistant sealing ensures durability.
Other capabilities of the 600EX II-RT include a stroboscopic mode as well as high-speed, first and second curtain sync settings. It is powered by 4 AA batteries and has a port for an optional external power pack. The rated recycle time is 0.1-5.5 seconds, or up to 0.1-3.3 seconds in Quick Flash mode. It comes with a bounce adapter, a hard CTO filter set, a mini stand, and an updated soft case that holds the flash and accessories.