Most of the time when we’re taking photographs we try to use a shutter speed fast enough to freeze any movement and prevent camera blur, either from subject movement or from camera shake.
But for more creative photography, it can also be fun to experiment with long exposure photography, and purposely create some kind of motion blur in our photographs.
This is created by either subject movement or from deliberately moving the camera. The most common use of long exposure photography movement is panning – (see my Previous blog )
Sometimes we may combine both subject and camera movement, by panning on a moving subject, such as a bird in flight, or a speeding cyclist.
At other times you might prefer to keep your camera still (usually on a tripod) and use long exposure photography to record a moving subject. There are lots of different possibilities – flowers blowing in the wind, moving people making ghost like figures in a static landscape, or flowing water creating a soft blur of white.
First, make sure that your ISO is set to its lowest number. Then check that you have a small aperture, such as f/16, f/22 or even f/32 .
If you still can’t get a long enough shutter speed, you may already have the answer in your camera bag. A polarising filter, which is normally used to saturate colours, will block enough light to give you a shutter speed about two stops longer – so your original setting of say 1/15 sec will become ¼ sec with a polariser.
Still not long enough? In that case, you will need a different type of filter, known as a neutral density filter. This reduces the amount of light which reaches your camera’s sensor, without affecting the colours in the scene. ND filters come in different “strengths”, with darker ones being more effective than lighter ones at reducing the light, and therefore giving you a long exposure.
In Long exposure photography you may find yourself using a shutter speed of several seconds, so a good stable tripod is essential!