Canon Speedlite Transmitter ST-E3-RT Instruction Manual - Page 44

Remote Release from a Slave Unit You can perform remote release (remote control shooting) from a flash set as a slave unit. For the operations, see the flash's instruction manual. When shooting with this function, the "Release Cable SR-N3" (sold separately) may be needed, depending on your camera. Cameras Compatible with Slave Unit Remote Release For EOS digital cameras released since 2012, such as the EOS-1D X, the "Release Cable SR-N3" is not needed. Cameras Not Compatible with Slave Unit Remote Release For EOS cameras other than the above that are compatible with E-TTL II/E-TTL autoflash and have an N3 type remote control terminal, the "Release Cable SRN3" (sold separately) is needed to perform remote release from a slave unit. As shown in the illustration, use the cable to connect the camera and the transmitter. Connect the release cable when the power of the camera and the transmitter is turned off. Shooting is not possible when focus cannot be achieved with autofocus. Focusing manually before performing remote release is recommended. The "Release Cable SR-N3" (sold separately) is for an N3 type remote control terminal. It cannot be used with cameras equipped with a remote control terminal other than the N3 type. Remote release is performed with "Single shooting" regardless of the camera's drive mode setting. When there are two or more master units, remote release is performed using the master unit with the lamp lit in green. 42