Canon EOS Rebel T6i W Instruction Manual

179The camera’s built-in flash can work as a master unit for Canon EX-series, external Speedlites having a wireless slave feature. It canwirelessly trigger the Speedlite(s) to fire via optical transmission.Be sure to read the instructions and cautions about wireless flashphotography (optical transmission) in the Speedlite’s instructionmanual.Regarding your Speedlite (slave unit), refer to its instruction manual andset it as follows. The settings other than the ones below for the slaveunit’s control are all set with the camera. Different types of Speedliteslave 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 channelas 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 shownbelow.(5) Face the slave unit’s wireless sensor toward the camera.*2Using Wireless FlashKSlave Unit Settings and PositionExample of Wireless Flash Set-upIndoorsOutdoorsApprox. 10 m/32.8 ft.Approx. 7 m/23.0 ft.Approx. 80°Approx. 5 m/16.4 ft.Approx. 7 m/23.0 ft.