The Canon Speedlite 600EX-RT - is a versatile flash with built-in radio control designed for photography professionals. The radio channel allows you to control the flash at a distance of up to 30 meters. There are 15 frequency channels available for radio control, you just need to select the channel with the best reception. At the same time, the flash also has a built-in remote control of the camera's shutter release (a second flash or a Speedlite ST-E3-RT transmitter must be installed on the camera. With synchronized shooting, the shutter can be released simultaneously with up to 15 cameras. Up to 15 Speedlites 600EX-RT can be used simultaneously for large subjects, interiors or portraits. Flash units can be assigned to one of three groups (up to five groups when using radio control), which can be controlled individually or together. High-speed sync allows the Speedlite 600EX-RT to operate at a wide shutter speed range, ideal for fill-flash in bright sunlight. A guide number of 60 (ISO 100, m) allows the Speedlite 600EX-RT to illuminate a large area, even when bouncing off walls and ceilings. Flash recharge now takes just 0.1 seconds. The flash head remains rotatable and allows you to adjust the bounce angle as it is convenient for the photographer. Reflected light photography, swivel head and variable bounce angle.