Shutter Speed
Now let’s turn to shutter speed. Depending on the make and model, your camera may offer shutter speeds from a
blazingly fast 1/8000s all the way down to 30 seconds. The shutter speed
controls the amount of time that the volume of light coming through the
lens (determined by the aperture) is allowed to stay on the film or
digital media in the camera. The same halving and doubling principle
that applies to aperture also applies to shutter speed.
Let me explain. Set the shutter speed control on your camera to 500.
This number denotes a fraction—500 represents 1/500 second. Now change
from 500 to 250; again, this represents 1/250s. From 1/250s you go to
1/125, 1/60, 1/30, 1/15, and so on. Whether you change from 1/30s to
1/60s (decreasing the time the light stays on the film/digital media) or
from 1/60s to 1/30s (increasing the time the light stays on the
film/digital media), you’ve shifted a full stop. Again this is important
to note since many cameras today also offer the ability to set the
shutter speed to one-third stops: 1/500s, 1/400s, 1/320s, 1/250s, 1/200s, 1/160s, 1/125s, 1/100s, 1/80s, 1/60s,
and so on. (Again, the underlined numbers represent the original, basic
stops while the others are the newer one-third options sometimes
available). Cameras that offer one-third stops reflect the camera
industry’s attempts to make it easier for you to achieve “perfect”
exposures. But as you’ll learn later on, it’s rare that one always wants
a perfect exposure.