Once, all cameras had a
female cable release thread in the shutter release button, allowing the
use of a long (often pneumatic, sometimes electric) cable release to let you
to trigger the camera from afar.
But these days, plenty of cameras (most?) don't have this
facility. In some cases, you can buy a dedicated electric cord that plugs into
the camera - but you'll certainly have to pay big dollars for it.
Remotely triggering a camera - any camera - is a problem no
longer! What we have here is a simple and cheap DIY project that will allow any camera to be fired from a good distance. With a little ingenuity it could even be adapted for radio control.
The camera doesn't have to be fitted with a threaded shutter
release button and it doesn't need a socket for an electrical cable release. In
fact, all that it really needs to have is a tripod mount (we haven't found a
"real" camera yet that doesn't!) and a button that gets pressed to take the
picture (ditto!).
It uses a small solenoid - a device which consists of a coil usually wound around some form of armature or plunger. When the coil is energised by current, the armature moves due to the magnetic attraction (or
repulsion) of the coil. It is this movement which is used to push the camera release button.
