Hampton Photo Arts

1. What is shutter speed?
Let’s begin with a basic definition of shutter speed. Now, the shutter in a digital camera is a thin sheet covering the CCD (think of the CCD as ‘film’). When this shutter opens, it exposes light from the exterior onto the CCD, hence allow a picture to be taken. The length of time that the shutter remains open is termed the shutter speed.

A key concept here – the longer the shutter remains open (i.e. the lower the shutter speed), the greater the amount of light that is allowed into the camera. And vice versa, the faster the shutter closes (i.e. the higher the shutter speed), the smaller the amount of light that is allowed into the camera.

2. How is shutter speed expressed?
If you look at modern digital cameras, shutter speeds are usually expressed as 1/8th of a second. The range of shutter speeds can be expressed as: 1, 1/2, 1/4, 1/8, 1/15, 1/30, 1/60, 1/125, 1/250, with each one being a fraction of a second. Each speed in this series is roughly half that of the one on the left.

3. Choosing the Correct Shutter Speed
Here’s the important question. How do you select the correct shutter speed when taking photos? Well, if you have a point-and-shoot camera, then it may not matter too much. Simply set the camera to automatic mode and snap the picture. The camera’s in-built auto exposure settings will take care of the shutter speed settings for you.

If, however, you like to play with manual settings and have a more advanced camera, then the choice of shutter speed clearly matters. What you need to remember is this – shutter speeds are very closely linked to movement. Use a slow shutter speed (say 1/60 or lower) if you want to introduce some blur in the picture to display speed in the subject. Remember, however, that a slow shutter speed will mean you need to hold the camera totally still for a longer period of time. If you can’t do this, your image will usually turn out bad. To work around the problem, use a tripod or steady your arms somewhere before taking the shot. As a general rule, if the shutter speed is 1/30 or slower, I’ll definitely use my tripod to steady the camera.

Use a fast shutter speed (say 1/125 or higher) if you need to capture a fast moving subject. Good examples include a passing car or a bird in flight. Now, one problem with fast shutter speeds is that you can totally miss the shot because the shutter opens and closes so fast. To workaround this, you can try one of two things. First, avoid the camera LCD - look through the viewfinder with one eye and use the other eye to spot the subject crossing the camera’s field of view. Second, you can try uses a lens that increases the field of view, allowing you more time to take the picture.

4. Make Use of the Light Meter
Another thing I find useful is to make use of the light meter in your camera. Most advanced digital cameras should have this feature. The light meter can tell you if there is too much or too little ambient light.

If it’s too bright, then you can set a fast shutter speed like 1/250 - the shutter will quickly open and close so that too much light doesn't get in. If it’s too dark, then do the reverse – use a slow shutter speed to give the camera time to absorb light into the camera.

5. Direction of Movement
OK, besides the speed of your subject, the direction of movement of your subject is also important. For a given shutter speed, if your subject is running perpendicular to the camera, then you need a faster shutter speed to capture the shot. If your subject is running at an angle towards the camera, then a slower shutter speed would suffice. An example is a photo of your pet dog. A dog running towards you would require a slower shutter speed then a dog running across you.