Give it some time

Take your long exposures beyond your Nikon's 30 sec limit. Adam Waring explores Bulb and Time modes

- Adam Waring

When you take a photograph, the shutter generally opens for a mere fraction of a second. But when you shoot in extremely low light conditions, such as at night or while using a strong ND filter, the exposure time required can extend to several seconds - or even minutes - long.

Your Nikon's built-in shutter speeds typically range from either 1/4000 or 1/8000 sec at the faster end, to as slow as 30 secs. But what if you need to shoot slower than this? You need to engage Bulb or Time mode. These enable you to close the shutter manually after a delay of your choosing.

Bulb mode is so-called because, back in the mechanical days of photography, the shutter could be held open manually by squeezing an air-filled rubber bulb that was physically screwed into the shutter button. The shutter would remain open for as long as the bulb was held, and this is also how the digital equivalent we call Bulb mode functions.

Bulb mode can be found on all Nikon cameras. However, it's not really very practical having to hold the shutter release for the duration of the entire exposure, particularly for several minutes - so more recent Nikons also have an additional Time mode. This requires two presses of the shutter release: the first opens the shutter, the second closes it. It really is a much more sensible way of doing things!