What is shutter speed? An explanation of how it can be used to freeze action, blur motion and take night shots. Also how it relates to light, exposure, stops, ISO and aperture for DSLR photography beginners.
What is shutter speed?
Let’s look at a couple of images:
In this shot, we have long trailing lights. You can just make out a bus on the left and a car number plate. In this shot we have a boy frozen in mid air. How do we achieve these amazing effects?
Yes, shutter speed!
The basic concept of shutter speed isn’t difficult to grasp but it helps if we first ask a fundamental question: what is a camera?
Well, a camera is simply a light-proof box with a door (a shutter) that lets in light and then closes again. The shutter can be open for a long time – hours even. Or a very short time: down to a 1/8000ths of a second. Everything that happens in front of the camera during that time – be it hours or a tiny fraction of a second, will be recorded.
There are no hard and fast rules about the exact shutter speeds to use in different situations. Afterall, few things move at the same speed all the time.
But let’s look at a few general examples:
Portraits: generally I try not to shoot any slower than 1/125 of a second. This is usually fast enough to freeze slight facial movements. In this shot you can see that subject’s face is sharp but there’s a slight blur to his hands to indicate movement.
Action: 1/400th of a second is fast enough to freeze this boy running. But if you look closely there’s still a little blur on his fist. 1/1000 would have frozen that.
It’s great fun to experiment with shutter speed and water. Here’s some handwashing at 1/400th of a second. And at 1/100th. I’m sure you know the classic long exposure waterfall shot – here’s my more modest attempt – at 15 seconds.
To freeze action you need a lot of light – so shooting on a bright, sunny day is perfect. Conversely, for a long exposure of seconds or minutes, low light – dusk or night time – is easier, although you can use a neutral density filter to reduce the amount of light entering the camera.
Shutter speed, like ISO and aperture, is measured in ‘stops’ and works on the basis of doubles and halves. If you double the shutter speed by one stop from 1/125 to 1/250, you are halving the light entering the camera. To halve the speed from 1/1000 to 1/500, you are doubling the light.
Shutter speed works in tandem with ISO and aperture. Assuming the light remains the same, if you change the shutter speed, you’ll need to compensate either ISO or aperture.
If you want to begin exploring shutter speed, it’s probably best to start by using TV – shutter speed priority – mode.
In this mode, you set the shutter speed and the camera decides the right aperture to get a correct exposure.
Shutter speed is fun and the best way to master it is to go out and experiment. So bye bye and happy shooting!