Shutter speed is how long the shutter stays open. The shutter on your camera allows light to enter and hit the image sensor (or film). Shutter speeds can vary from very fast (1/2000th of a second) to very slow (1/10th of a second or longer). To avoid a blurry photo, you'll want to use a tripod with slower shutter speeds, and if the subject is fast-moving, you'll want to boost the shutter speed to a higher number. (That may mean that you'll need to adjust your ISO to a higher number too, but I will talk more about that in another post.)

This photo of some fun 4th of July fireworks was taken at about f/8 at 6" sec. (The shutter was open for 6 full seconds.) I definitely had to use a tripod, and I used a remote to make sure that the camera would not move when I pressed the shutter button.


This photo of my little boy swinging was taken at about 1/800th of a second. He was moving fairly fast, and I wanted to stop the action and avoid him being blurry. Faster shutter speeds freeze action and avoid motion blur.