The Enthusiast's Guide to Night and Low-Light Photography

12. WHY YOU NEED BULB MODE

CAMERAS ALLOW YOU TO USE a wide range of shutter speeds from 1/8000 of a second all the way to 30 seconds. But what if you want to use a really long shutter speed, like 10 minutes or longer? This is where the Bulb shutter speed setting comes into play. This mode allows you to keep the shutter open for as long as you want. This isn’t just a useful setting—it is imperative for those really long exposures (anything over 30 seconds).

You can only access the Bulb mode when the camera is in Manual exposure mode. The other exposure modes either require you to set the shutter speed before taking the picture (Shutter Speed Priority ...