What is shutter speed? Shutter speed is one of the three parts of the exposure triangle in photography, the other two being ISO and Aperture. Shutter speed is the amount of time that the shutter is open, used for creating dramatic effects by either freezing action or blurring motion.
What is Shutter Speed in Photography
Shutter speed is a measurement of the time the shutter is open, shown in seconds or fractions of a second: 1 s, 1/2 s, 1/4 s … 1/250 s, 1/ 500 s, etc. The bigger the denominator the faster the speed. (For example 1/1000 is much faster than 1/30.) The faster the shutter speed, the shorter the time the image sensor is exposed to light; the slower the shutter speed, the longer the time the image sensor is exposed to light.
Changing the shutter speed one step faster, say from 1/60 s to 1/125 s, is referred to as ‘increasing shutter speed by one step' and halves the amount of time the shutter is open. Whereas changing the shutter speed one step slower, from 1/125 s to 1/60 s, is referred to as ‘slowing shutter speed by one step' and doubles the amount of time the shutter is open.
What Shutter Speed to Choose
When considering what shutter speed to use in a photograph you should always ask yourself whether anything in your scene is moving and how you’d like to capture that movement. If there is movement in your scene you have the choice of either freezing the movement or letting the moving object intentionally blur.
To freeze movement in a photograph you’ll want to choose a faster shutter speed and to let the movement blur (like the bottom photograph above) you’ll want to choose a slower shutter speed. The actual speeds you choose will vary depending upon the speed of the subject in your shot, and how much you want it to be blurred.
Another thing to consider when choosing shutter speed is the focal length of the lens you’re using. Longer focal lengths will accentuate the amount of camera shake you have, so you’ll need to choose a faster shutter speed. The ‘rule’ of thumb to use with focal length is to choose a shutter speed with a denominator larger than the focal length of the lens. For example, if you have a lens that is 50mm you can shoot at 1/60th or higher, but if you have a 200mm lens you’ll want to shoot at around 1/250 or higher.
Shutter Speed, Aperture, and ISO
Keep in mind, as you change shutter speed you’ll need to change the ISO and Aperture to compensate for it.
When you speed up your shutter speed one stop (for example from 1/125th to 1/250th) you’re effectively letting half as much light into your camera. To compensate for this you’ll probably need to increase your aperture one stop (for example from f/16 to f/11). The other alternative would be to choose a faster ISO rating, moving from ISO 100 to ISO 400 for example.
Now that we've covered what is shutter speed in photography, it's time to get out and have a little fun movement and photography.