Shutter speed is an easy topic to understand. It’s simply the amount of time that the shutter in your camera stays open (in the up position) exposing the sensor in digital cameras (or the film) to light coming through the lens. The longer the shutter is open the more exposure the sensor has to light making the image that will be produced brighter. Too much time in the open position and you will see nothing but a white frame and too little time in the open position can produce a solid black image. Just the right amount of shutter open time combined with the correct aperture setting will produce a well exposed image that is pleasing to the eye.
Shutter speed doesn’t only affect the exposure of the image though; it can also affect the sharpness of the image. A very slow shutter speed may produce the correct exposure but cause a blurry photo if the subject is moving. Moving subjects can be stopped with a fast enough shutter speed. In some case blurring may prove useful. If you are photographing a fast car, the blur can add the feeling of motion to the image. The trick is knowing how much blur to allow.
This image was created on a very bright summer day with the sun slightly behind me using a shutter speed of 1/500 second and an aperture of f/8. I could have used a slower shutter speed to show the rotation of the blades but that would have probably blurred the helicopter. Photo taken along the Potomac River in Washington D.C.
This image was created using a tripod and setting the aperture to f/8, ISO to 100, and the shutter speed to 1/6 second. It was raining when I took the photo and there was not much light even though it was early afternoon. The slow shutter speed is what produced the silky white texture in the waterfall. Photo taken in Costa Rica.
We will visit shutter speed more in other articles and blog posts. Like all other aspects of your camera, practice. Take photos using your tripod and hand held varying the shutter speed and review the results so that you begin to build a mental database of settings and results.