Can someone explain the 'bulb' setting please? please?

Question

what it it used for, any details you have!

Answer 1

Bulb leaves the shutter open for as long as its depressed. In the old days, a squeeze bulb attached to a thin hose was used to forced air to open and close the shutter. Thats where the name bulb setting comes from.

Answer 2

It is the setting you use when you have to keep your cameras shutter open longer than 30 seconds.

Shooting things like star trails, fireworks, head and tail light trails on freeways and the like.  Of course you will have to mount the camera on a tripod and use a remote cable release to use it well.

There used to be two settings ... "B" Bulb and "T" Time.  For some reason the time setting has been dropped by camera makers.

Answer 3

The "bulb" setting on a camera allows the shutter to remain open for as long as the shutter-release button is held.

The term originated long ago when cameras had pneumatic shutters actuated by an air-filled bulb attached to the shutter mechanism with flexible tubing. The photographer would physically squeeze the rubber bulb forcing air pressure to open the camera's shutter, then release the bulb to close it. In that way, the film exposure was controlled by the length of time the shutter was manually held open.

In modern/digital cameras, the mechanics have changed but the concept remains the same.

Check Google or Wikipedia for more info. Aloha.