As a Canon top-of-the-line flash, the Speedlite 600EX-RT takes the best features from existing models and adds functionality for enhanced digital photography. The 600EX features a new wireless multiple flash system using radio wave communication that provides more precise control over as many as five groups of flashes. There's also more power, with a guide number of 197' (60 m) at ISO 100, a zoom flash head that covers a 20-200mm range, and updated AF assist beam that's compatible with Canon's 61-point High density Reticular AF.
The included color filter holder and two orange color filters multiply your creative options--the holder is compatible with Canon as well as third-party gelatin filters. The 600EX offers several other improvements--it's been redesigned, with a metal hot shoe, improved dust- and water-resistance and body strength, plus the ability to control flash functions and settings from the camera menu. A dot matrix LCD panel and backlit button deliver much-improved visibility.