Flashbulbs are harder to find nowadays, so the original flash for the C3 may not be a practical choice for flash photography. If your camera has 5 marked shutter speeds, it is capable of synchronizing with electronic flash, if you can find an adapter to convert the built-in flash socket to a PC socket.

To use the original flash, unscrew the bottom cap of the flash and insert two fresh size C batteries with the positive ends up (facing away from the bottom cap) on both batteries.

To attach the flash, simply plug it into the side of the camera. Do not have a bulb in the flash when attaching it.

To use the flash, push a flashbulb into the socket in the reflector as far as it will go. After the bulb is flashed, use the button on top of the flash to eject the bulb.

Never use flashbulbs in an area where flammable liquids or vapors may be present.