Understanding Shutter Speed.
183 sec at f / 20 24mm lens ISO100
Taking control of the shutter speed – essentially, controlling how long light is allowed to get through to your camera's sensor, or light-sensitive film – is one of the key creative skills in photography.
Point and click photographers and most smartphone users never give a second thought to shutter speed, but picking a very fast shutter speed, or a very slow one, can give dramatically creative results. Here's a quick rundown of some of the cool stuff you can do by controlling shutter speed.
1) Setting shutter speed – a recap
157 sec at f / 22 100mm lens ISO100
The easiest way to set the shutter speed yourself is to switch to Program Shift or Shutter Priority mode (also known as Tv mode on Canons).
It is then very easy to move the shutter speed up and down using your camera's dial, and the camera will then automatically set what it thinks is the right aperture for the shutter speed you have chosen.
The result will (hopefully) be a balanced exposure. Alternatively, you can switch to Manual mode and set shutter speed and aperture independently of each other. Note also that ISO affects shutter speed – higher ISOs will give you faster shutter speeds.
2) Going slow
129 sec at f / 20 21 mm lens ISO 100
Setting a slow shutter speed, also known as making a long exposure, means the shutter curtains stay open for longer, so more light is reaching the sensor. Hence it's ideal for low light and night shots, and you get some cool side-effects of the shutter being open for longer – car headlights appear as swooping light trails, for example.
Fast moving water is also slowed to an attractive blur. Anything slower than 1/15 second will give you a blurred waterfall or water torrent, so slow right down for a very smooth, milky look. You may need to use an ND filter to prevent overexposure in daylight (remember, lots of light is getting through at slow shutter speeds).
If you use an ND filter to shoot the sea, you can extend a slow exposure of, say, 1/8 sec to more than two minutes, making the sea look like like perfectly still glass.
3) Go very slow
2047 sec at f / 5.6 56mm lens ISO 400
At the far extreme of slow shutter speeds, you can choose Bulb mode, which means that the shutter stays open for as long as the shutter button is depressed.
It's overkill for getting effects like traffic trails, but comes in very handy for photographing fireworks, star trails and lightning. It goes without saying that you must use a tripod to avoid gross camera shake in Bulb mode, along with a cable release.
4) Speeding up
1/4000 sec at f / 4.5 17mm les ISO100
At the other extreme, much faster shutter speeds enable you to capture fast moving objects with great clarity, almost as if they are standing still. This is a curse and a blessing – while it's great to see a 200Mph F1 car frozen in time, if you are not careful it can look as if it's parked on the track.
This is one of the reasons that many motorsports photographers combine a frozen vehicle with some selective blur (panning, for example) to give a sense of speed. Very fast shutter speeds are also good for wildlife but again, you need to be careful that a bird, for example, doesn't look totally static.
This is why many photographers like to shoot a bird landing in water. The water droplets exploding around it create a much more dynamic image than if it was just frozen mid-air.
Further Study
Low Light Landscape Photography 4 week online photography course with Tony Worobiec.