Canon EOS Rebel T6i EF-S 18-55mm IS STM Lens Kit Instruction Manual - Page 179

Using Wireless FlashK The camera's built-in flash can work as a master unit for Canon EXseries, external Speedlites having a wireless slave feature. It can wirelessly trigger the Speedlite(s) to fire via optical transmission. Be sure to read the instructions and cautions about wireless flash photography (optical transmission) in the Speedlite's instruction manual. Slave Unit Settings and Position Regarding your Speedlite (slave unit), refer to its instruction manual and set it as follows. The settings other than the ones below for the slave unit's control are all set with the camera. Different types of Speedlite slave units can be used and controlled together. (1) Set the external Speedlite as a slave unit. (2) Set the Speedlite's transmission channel to the same channel as set on the camera.*1 (3) For flash ratio control (p.187), set the slave unit's firing group. (4) Position the camera and slave unit(s) within the range shown below. (5) Face the slave unit's wireless sensor toward the camera.*2 Example of Wireless Flash Set-up Indoors Outdoors Approx. 10 m/32.8 ft. Approx. 7 m/23.0 ft. Approx. 80° Approx. 5 m/ Approx. 7 m/ 16.4 ft. 23.0 ft. 179