CHOOSING THE MANUAL SLAVE MODE
Your Master Flash (the flash used to trigger the slave) may emit more than one burst of light in quick succession before the main flash. These are called pre-flashes, which are controlled by the camera and fired to help the camera to determine the correct exposure for the photograph or to reduce the "red-eye" effect. If the slave flash is not set to the correct mode, it may fire before the camera’s shutter opens.
To ensure that the slave flash fires at the correct time, there are three slave modes available in this flash to help you to synchronize with the master flash:
Mode 0 The slave flash fires instantly when it “sees” the first light burst from the master flash
Mode 1 & 2 The slave flash ignores 1 (Mode 1) or 2 (Mode 2) pre-flashes. These modes should be used when the master flash is set to TTL or any automatic modes. Always take a test shot to check which mode you should use in order to synchronize the slave flash with the master flash’s main flash.
If you are using your camera’s built-in flash or an external flash attached to the camera as the master flash, you should note that this flash may emit a series of quick flashes lasting for a second or more when the camera’s red eye reduction feature is activated. As a result, no appropriate slave modes can be selected for synchronization. You should turn off the red eye reduction feature in your camera when using this flash as a slave flash.
22 Choosing the manual slave mode
