Shutter Speed and Motion Blur

One reason to slow the shutter down (expose longer) is to allow a smaller aperture and therefore deeper depth of field. But you might also want a slower shutter, say 1/30^th of a second, to purposely blur moving objects in your photo. This gives a sense of speed, quite different than the “frozen” action you get with higher speeds.

It’s simple to explain why: a car or runner covers a lot more ground moving across your frame in 1/30^th of a second than 1/500^th of a second, so they blur across the film instead of being frozen in one spot. Good or bad? It depends what you’re aiming for – see below!

One thing to remember: blurring as a result of camera shake is definitely a bad thing! At slower shutter speeds or with a lot of zoom, use a tripod or other steadying device.

Below are some shots of mine illustrating the effect of shutter speed:

Camera still, 1/30 : car blurs, background clear	Camera pans with car – car clear, background blurred
Underexposed? A slower shutter speed gives you more light, but more blur! (Yes, everyone in Aurora drives a red van…)
Fast shutter speeds (1/500^th) freeze the action
Slower shutter speeds (1/60^th, 1/30^th) give a beautiful sense of motion
A long exposure at dusk with motion-blurred headlights. ( 8 second exposure (tripod used!), F/16 and low ISO to avoid over-exposure )
Motion blur (check the hands) combined with other effects can give frightening results!