What is Shutter speed ?

A Tripod and a a Shutter speed of .4 seconds allowed me to capture the motion of the fire juggling
                      

             Every Digital camera has a light sensitive material behind the shutter. The shutter in most all digital cameras today is called a focal plane shutter. A focal plane shutter is comprised of two metal curtains. When the cameras shutter release is depressed the first curtain rises exposing the sensor for a specific amount of time and then a second curtain (also known as the Rear Curtain) quickly follows to cover up the sensor.
There are 3 components that determine how much light is recorded by the sensor, Shutter speed, Aperture, and ISO. each one has its own job and affects the photo in a different way. Today we will focus specifically on Shutter speed.

this jogger was photographed at a shutter speed of 1/500 of a second with a 50mm lens, i selectively focused on the jogger using an fstop of f/2.0

                Shutter speed is referring to the amount of time that the Film or digital light sensitive sensor is exposed, usually seen in fractions of a second. for ex: 1/60, 1/125, 1/250. Most Digital SLR cameras shutter speeds can range from 30 seconds up to 1/4000 of a second and some can even reach 1/8000 of a second! In most instances the photographer will want to choose a shutter speed that is fast enough to "freeze" motion so there is no blur due to camera shake or subject movement. 1/60 of a second is generally the slowest recommended speed for handheld photos of non moving subjects. (personally i like to stay above 1/125.) One easy way to experiment with different shutter speeds is to set your Cameras Mode dial to S (Shutter Priority) or on canon TV (Time Value), this enables you to select a shutter speed and the camera will automatically select an appropriate aperture for correct exposure*. (*Depending on the capabilities of the camera. if the scene does not have enough light for the selected shutterspeed the LCD will display a warning sign that the photo may be underexposed. solutions include choosing a slower Shutterspeed, moving to a brighter area, or raising the ISO.)

        

Shown here: A shutter speed is 1/125 of a second. On some DSLRs the "1/" is not shown it simply just shows the number eg: 1/125 = 125

When photographing moving subjects like birds in flight or a fast paced sports game you would want to have your camera set to 1/500 of a second or faster to freeze the action.

  a shutter speed of 1/1000 of a second was used to "Freeze" this Seagull mid flight

            

      Sometimes you may want to choose a slow shutter speed to blur motion or for creative effect.

Ever wonder how the pros get those beautiful waterfall shots? The camera was on a tripod using a shutter speed of 2 seconds long! rendering the moving water silky smooth

Some lenses have internal stabilizers which enable u to capture sharp photos at slow shutterspeeds without a tripod! this is known as IS (Image Stabilization) on Canon cameras and VR (Vibration Reduction) on Nikon cameras

Using a VR (stabilized) lens and gently pressing the shutter button enabled me to get reasonably sharp photo at a shutter speed of 1/2 a second Handheld

In conclusion Shutter speed affects two things
1) Exposure. The amount of light that reaches the sensor

2) Motion. How much blur is recorded due to camera or subject movement

A technique known as Panning. Panning is when the photographer moves the camera at the same speed of a moving subject thereby keeping them sharp while the background becomes a pleasing blur. it can take some practice to get a good pan but the results are well worth the effort! a shutter speed of 1/25 of a second was used for this photo

              I hope this article has given you an insight as to how shutter speed works and how choice of shutter speed can greatly  impact  the look and feel of a photograph. Next time we will explore the role of Aperture, how it works and how to use it creatively to obtain visually appealing images. Feel free to leave your questions and comments below.

Update: here is the blog post on Aperture