Alright, last week we learned all about aperture and how it affects the amount of light and depth of field in your image. This week, we’re moving on to another important component of the exposure traingle: shutter speed!
What is Shutter Speed?
If you were to think of your camera like an eye, the camera’s shutter would be similar to your eye lid. After light passes through the lens, the camera’s shutter opens allowing the light to hit the camera’s sensor. Shutter speed simply refers to the length of time that the shutter is open.
Measuring Shutter Speed
Because shutter speed refers to a length of time, it is measured in seconds. Most of the time, the shutter is open for such a short period of time that the shutter speed is measured in fractions of seconds and is written as “1/x.” The larger the denominator, the faster the shutter speed. For example, a shutter speed of 1/2000th of a second is much faster than a shutter speed of 1/60th of a second.
How does Shutter Speed Affect Exposure?
Just like aperture, shutter speed affects the amount of light that reaches the camera’s sensor. The longer the shutter stays open, the more light that passes through and the brighter the image. So a long shutter speed, like 1/60th of a second, would allow more light to enter the camera than a shutter speed of 1/2000th of a second. In the images below, you can see how changes in shutter speed change the exposure of the image. The only setting that I changed was the shutter speed – the aperture and ISO remain constant.
Using Shutter Speed to Capture Motion
One great thing about shutter speed is that you can use it to either show or stop motion in an image. A fast shutter speed will seem to freeze a moving object. On the other hand, a long shutter speed will allow you to depict an object moving through your image.
In the images below, you can see how changing the shutter speed changes the way motion is depicted. The left-most image is shot with a fast shutter speed of 1/2000th of a second and appears to stop the motion of the water. Decreasing the shutter speed to 1/5 of a second, as shown in the right-most image, allows you to capture the movement of the water as it flows off the fountain.
Testing it Out
You can experiment with shutter speed at home! I recommend setting your camera to “shutter priority” mode (“Tv” if you shoot Canon, “S” if you shoot Nikon). In this mode, you determine the shutter speed you want and the camera adjusts the other settings so that your image is properly exposed. Find an object that is moving (water works great!) and take photos with various shutter speeds. Pay attention to how different speeds change the way the motion looks!
Note: When using a slow shutter speed, your images may be blurry due to the movement of your hands as you hold the camera. This is called camera shake. To avoid camera shake you can use a tripod or use a minimum shutter speed of “1/focal length”. So if you were using a 50mm lens, you would use a shutter speed of at least 1/50 sec.
