For Canon speedlight, user need to TAPE the 4 pins of the speedlight or else user must OFF and ON the flash after each fire.
Seagull SYK-3 Flash Slave Trigger Wireless Hot Shoe Sync Adapter for hot shoe mount flash, compact and sturdy with a standard hot shoe seat on the top and a standard 1/4"- 20 thread screw socket for tripod on the bottom.
This flash remote controller is optical theory making the master flasher to control remotely the auxiliary one to flash synchronously without the need of connecting wires. Because slave trigger gets its working power from the flash attached to it and therefore it is battery-free. The item features small in volume, good-looking in exterior, high in flexibility and stable in performance.
Triggered by external flash light. No battery required.
Suitable for Nikon, Canon, Olympus, Pentax, Sunpak, Sigma, Nissin, Metz, etc. flashes that use standard ISO shoe. Trigger by another flash light from other source.
How to use?