Bulb Mode

Camera shutters usually have a setting marked. When you pick the B setting the camera holds the shutter open while the shutter button is pressed. You can use it to take pictures in poor light, or if you want to get artistic effects like light trails. The B stands for “bulb” mode.

Most folks think that bulb means “flash bulb” but this is not the case. It actually refers back to a time in the past when camera remote control was achieved by using shutters that could be fired pneumatically. One end of the tube was attached to a piston on the shutter, the other to a rubber bulb you could squeeze to trigger it.

I’ve been able to recreate this using some 6.5mm laboratory tube and an air blower. I would have liked to have had thinner tube, but putting a cable tie on the end helps it fit. It works well, although you have to give the bulb a hefty squeeze.