What Is Bulb Mode on a Camera?
Bulb mode simply allows the photographer to take a picture for as long as the shutter is depressed (that means pushed down, not sad…). You can use bulb mode by choosing a manual mode or shutter priority, then start scrolling your selector wheel all the way to the end of the shutter speeds. After 25″ (25 seconds), 30″, it will show “bulb” or simply the letter “b” on some cameras. Now you’re in bulb mode. This means the camera will keep taking a picture until your finger comes off the shutter button.
Bulb mode is mostly used for long exposures at night. The main advantage is that it allows the photographer to achieve shutter speeds longer than the 30 seconds (displayed 30″ on the camera) that is allowed on most DSLRs.
No one in their right mind would stand next to the camera with their finger pressing down the shutter button for an ultra long exposure. Bulb mode is usually used in conjunction with a cable release. You can pick up a cable release for about $10 for most DSLRs on Amazon. It is simply a wired remote control that allows the photographer to lock the shutter button to take LONG EXPOSURES.