A slow shutter speed can be used to allow more light to reach the camera’s sensor, as well as to create implied motion in pictures.

Introduction

Shutter speed is a time value expressed in seconds or fractions of seconds. It is one of two factors (the other being aperture size) that determine how much light reaches the camera’s sensor. The slower the shutter speed, the longer the shutter is open. The longer the shutter is open, the more light that is allowed into the camera and the brighter the resulting picture. Shutter speeds generally range from 1/500^th of a second (fast) up to 30 seconds (slow).  A shutter speed longer than 1/30^th of a second is usually considered slow.

In extreme low light situations, such as this canyon, the only option for a properly exposed picture is to use a very slow shutter speed. In this picture the shutter speed was 8 seconds with an aperture of f/11.

When using a slow shutter speed it is a good idea to employ a tripod and cable release to keep the camera absolutely still. Any vibration of the camera will result in a blurred photo.

Antelope Light Ray (Arizona, US)

In close-up photography, the shallow depth of field (the small area of sharpness) provides an added challenge for the photographer. Because of the optical properties of the camera lens, the depth of the area in focus decreases as we move closer to our subject. One can compensate for this by using a smaller aperture.  In the picture of a spider, an aperture of f/22 was required to maintain a sufficient depth of field and keep the entire body of the spider in focus.  In order to compensate for the smaller aperture, a slower shutter speed - 1/4 of a second - was needed to allow enough light into the camera for a proper exposure. We used tripod and cable release to prevent blurring.

In this case, a slow shutter speed is used to allow a smaller aperture to provide more depth of field – area appears to be sharp - in the area of focus.

Black and Yellow Argiope (On, Canada)

In this picture, when a slow shutter speed, ½ of a second, was used to capture the ferris wheel, the moving cars became a blur. In contrast, the stationary objects in the picture – the supporting structure and the Giant Wheel sign – remained in focus. Once again, a tripod and cable release were used.

When blurred and focused objects are combined in the same image, a sense of motion is implied. In this photo there is no doubt that the “Giant Wheel” is in motion.

Giant Wheel (Toronto, On, Canada)

Panning, a technique commonly used in film and video, can also be used with a still camera. In this picture, the photographer moved the camera to keep pace with the wheelchair racer. The result was a sharp image against a blurred background. In this case a shutter priority of 1/30th of a second was used. In other situations, it may be necessary to experiment with different shutter speeds.

Wheelchair Racer (Toronto, On, Canada)

Conclusion

Slow shutter speeds are a useful photographic technique. They can be used in low light situations, when dramatic action pictures are the photographer’s goal, and macro photography. Experimenting with shutter speed may allow you to achieve just the effect you are looking for.