Product DescriptionThe Speed lite 600EX II-RT delivers impressive power, responsive performance and advanced, wireless communication for those who demand the very best in flash photography. Featuring improved continuous performance up to 2.0x* faster than its predecessor, the Speed lite 600EX II-RT performs at a phenomenal speed, and reliably at that - new Quick Flash settings and a flash-readiness indicator help ensure priority shutter operation, even when the flash isn’t fully recharged. It’s also built for fast, convenient use virtually anywhere for any situation, with improved combination button and dial controls, a refined dust- and water-resistant body and new accessories tailor-made for enhanced lighting effects. For speedy and comprehensive flash photography on the go, the Speed lite 600EX II-RT delivers portable, professional performance with ease.From the ManufacturerThe Speedlite 600EX II-RT delivers impressive power, responsive performance and advanced, wireless communication for those who demand the very best in flash photography. Featuring improved continuous performance up to 2.0x* faster than its predecessor, the Speedlite 600EX II-RT performs at a phenomenal speed, and reliably at that - new Quick Flash settings and a flash-readiness indicator help ensure priority shutter operation, even when the flash isn’t fully recharged. It’s also built for fast, convenient use virtually anywhere for any situation, with improved combination button and dial controls, a refined dust- and water-resistant body and new accessories tailor-made for enhanced lighting effects. For speedy and comprehensive flash photography on the go, the Speedlite 600EX II-RT delivers portable, professional performance with ease.*As compared to the Speedlite 600EX-RT. When used with optional Compact Battery Pack CP-E4N. Zoom flash head covers a wide range of 20-200mm; maximum guide number is 197 ft./60m at ISO 100.Click here for larger imageEquipped for flash photography in a wide variety of situations, the Speedlite 600EX II-RT has a guide number of 197 ft. (60m) at ISO 100 to help achieve the lighting you desire. It offers 20mm to 200mm coverage, and when the extendable wide panel is pulled out, flash coverage moves as wide as 14mm. Plus, to maximize power and minimize energy consumption, the Speedlite 600EX II-RT can be directed to zoom in accordance with the camera’s image sensor size (full-frame and APS-C). Improved performance of continuous flash by approx. 1.1 to 1.5x* for fast firing (up to 2.0x* if used with optional Compact Battery Pack CP-E4N).Click here for larger imageThe Speedlite 600EX II-RT offers significant improvements in continuous flash performance. Engineered with a combination of highly heat-resistant material, a revised optical design for suppressing gain in the panel’s temperature, plus a redesigned interior structure, the Speedlite 600EX II-RT sees speed gains of 1.1 to 1.5x* self-powered, and 1.5 to 2.0x* when used with the optional Compact Battery Pack CP-E4N. An improved flash control algorithm and a redesigned Quick Flash function help to minimize unfired flashes for more reliable, continuous operation.*As compared to the Speedlite 600EX-RT. Wireless flash shooting support is available for both radio and optical transmission, offering users greater functional range when using a flash.Click here for larger imageFor comprehensive lighting setup on the go, the Speedlite 600EX II-RT offers a number of options for both wireless flash and multi-camera operation. When used with a compatible flash, or flash driver mounted on camera, the Speedlite 600EX II-RT can serve as a slave unit in an optical setup, at distances of up to 49.2 ft./15m when indoors and 32.8 ft./10m when outdoors. In addition to optical wireless flash, the Speedlite 600EX II-RT is capable of radio transmitted wireless flash where the flash units need not be in visual proximity to one another and transmission distance is extended up to 98.4 ft./30m