Canon Speedlite 600EX-RT Instruction Manual - Page 52

' Radio Transmission Wireless Flash Shooting Shooting with a Different Flash Mode set for Each Group (p.65) Auto external flash metering Ceiling E D E-TTL II A B Manual flash C Manual flash Manual flash * The flash mode settings are indicated only as an example. Difference between Radio Transmission and Optical Transmission Wireless shooting using radio transmission has advantages over wireless shooting using optical transmission, such as being less affected by obstacles, and not having to point the slave unit's wireless sensor toward the master unit. The main functional differences are as follows. Function Transmission distance Firing group control Slave unit control Channel Wireless radio ID Radio Transmission Approx. 30 m (98.4 ft.) Up to 5 groups*1 (A/B/C/D/E) Up to 15 units Auto, Ch. 1 - 15 0000 - 9999 Optical Transmission Approx. 15 m (49.2 ft.) (indoors) Up to 3 groups (A/B/C) No restriction Ch. 1 - 4 - Operations Test flash firing - from slave Modeling flash *2 - unit Release *3 - *1, *2 and *3: Some restrictions apply depending on the camera that you use. (Refer to *1: p.51, 65; *2: p.67; and *3: p.68.) 50