The Camera Shutter and Shutter Speeds
The function of the camera shutter is to open and then close after a specific length of time so that light coming through the camera lens may reach the image sensor. The characteristics (intensity and colors) of the light is read by the image sensor and those characteristics are reproduced as a picture. The length of time that the shutter remains open during an exposure (when the shutter release is pressed) is called the shutter speed.
The shutter speed directly affects the look of motion in an image as well as the exposure of the image. Exposure refers to whether an image is too dark (underexposed), too light (overexposed), or just right.
Shutter Speed Chart: The shutter speed is usually expressed in fractions of a second as shown below. The "B" stands for Bulb and is a setting that the photographer can use to leave the shutter open as long as needed.
The shutter speed directly affects the look of motion in an image as well as the exposure of the image. Exposure refers to whether an image is too dark (underexposed), too light (overexposed), or just right.
Shutter Speed Chart: The shutter speed is usually expressed in fractions of a second as shown below. The "B" stands for Bulb and is a setting that the photographer can use to leave the shutter open as long as needed.
The chart above lists some of the standard shutter speeds as full steps. Changing the shutter speed from any one of those settings to the adjacent one will either double or cut in half the amount of time the camera shutter remains open. Please note that, besides the shutter speeds listed above, you will see shutter speed increments in your camera that fall between the ones listed above.
Shutter Speeds and Motion: In addition to allowing light to reach the image sensor, the camera shutter will affect how any motion in a scene will appear in your image. Motion in a photo image can be "frozen" or appear as blurred. Take a look at the pictures of the 2 cars below.
Image#1, Shutter Speed 1/60 second, Shows Motion Blur
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Image #2, Shutter Speed 1/400 second, Freezes Motion
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The car in picture #1 was moving around 30 mph. Notice that just about everything in the image is in focus except the car. This is an example of what is known as motion blur.
The car is not in focus because the shutter speed of 1/60 sec was not fast enough to "freeze" it's motion. In some cases this type of blur might be desirable because it actually conveys a sense of motion. However, if you want your moving subject to be in focus, you will need to use a faster shutter speed that will freeze the motion.
The car in picture #2 was also moving about 30 mph, yet the car and everything else in the scene is in focus. That is because in this case a faster shutter speed (1/400 sec) was used. The shutter speed was fast enough to freeze the motion without the blur. The shutter speed of 1/400 worked well to freeze the motion in this case, but when taking pictures of faster moving subjects, a shutter speed of 1/500 or higher is usually a better choice.
The car is not in focus because the shutter speed of 1/60 sec was not fast enough to "freeze" it's motion. In some cases this type of blur might be desirable because it actually conveys a sense of motion. However, if you want your moving subject to be in focus, you will need to use a faster shutter speed that will freeze the motion.
The car in picture #2 was also moving about 30 mph, yet the car and everything else in the scene is in focus. That is because in this case a faster shutter speed (1/400 sec) was used. The shutter speed was fast enough to freeze the motion without the blur. The shutter speed of 1/400 worked well to freeze the motion in this case, but when taking pictures of faster moving subjects, a shutter speed of 1/500 or higher is usually a better choice.
Image #3, Shutter Speed 1/800 second
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Image #4, Shutter Speed 1/15 second
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Another example of how the shutter speed affects the look of motion in an image is shown in the two pictures of the water fountain above. Image #3 was taken using a pretty fast shutter speed of 1/800 second. As you can see, most of the water droplets are "frozen" in mid air.
On the other hand, image #4 was taken with a very slow shutter speed of 1/15 second and the water shows as a silky blur. Both of the shutter speeds used were effective in creating nice images. The choice as to whether to use a very fast or very slow shutter speed depends on the effect the photographer wants.
Choosing a Shutter Speed: If there is motion in a scene that you are photographing, the best shutter speed to use will vary depending on the speed of that motion, or the desired effect of the motion. (subject frozen or blurred) Listed below are some common picture taking situations and shutter speeds that can be used as starting points.*
On the other hand, image #4 was taken with a very slow shutter speed of 1/15 second and the water shows as a silky blur. Both of the shutter speeds used were effective in creating nice images. The choice as to whether to use a very fast or very slow shutter speed depends on the effect the photographer wants.
Choosing a Shutter Speed: If there is motion in a scene that you are photographing, the best shutter speed to use will vary depending on the speed of that motion, or the desired effect of the motion. (subject frozen or blurred) Listed below are some common picture taking situations and shutter speeds that can be used as starting points.*
*Depending on the available light, adjustments to the lens aperture and ISO settings may be required to use the desired shutter speed. Check the Camera Exposure Basics tutorial on how adjustments may be made.
Use a Tripod for Slower Shutter Speeds: It is important to note that when you use very slow shutter speeds, (1/30 second or slower) it is a good idea to use a Tripod. Camera shake and the blur that comes with it increases greatly at slower shutter speeds. When the camera is hand held and a very slow shutter speed like 1/15 second is used, there is a strong possibility that the whole image will be out of focus due to camera shake. Check the Night Photography tutorial for more on this subject.
The Camera Shutter and Exposure: The camera shutter, lens aperture, and iso settings work together to produce images that are "correctly" exposed or exposed to the photographers preference. Those three functions are commonly referred to as the "Exposure Triangle". Check the Camera Exposure Basics page for more on how they work together
As far as the exposure of an image, the shutter speed settings can be adjusted so that the camera will produce lighter or darker images by increasing or decreasing the length of time that the shutter is open.
As far as the exposure of an image, the shutter speed settings can be adjusted so that the camera will produce lighter or darker images by increasing or decreasing the length of time that the shutter is open.
Image #5, Shutter Speed 1/250 Second, Aperture F11, ISO 800
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Image #6, Shutter Speed 1/125 Second, Aperture F11, ISO 800
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Image #7, Shutter Speed 1/60 Second, Aperture F11, ISO 800
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The three pictures above are examples of how the shutter speed can affect the exposure (lightness or darkness) of an image. The camera settings for all three pictures was the same except for the shutter speed. Take note of the shutter speed listed under each image.
Any decrease or increase in the shutter speed will cause the image to be lighter or darker. That is, as long as the lens aperture and ISO settings remain the same. Images will be lighter as the shutter stays open longer and the image sensor is able to absorb more light. Pictures will be darker when the shutter is open for a shorter period of time.
Take another look at the 3 pictures above and take note of the following: a 1/60 sec shutter speed will keep the camera shutter open about twice as long as a 1/125 sec shutter speed. On the other hand, the 1/250 sec shutter speed leaves the camera shutter open half the length of time as the 1/125 shutter speed. So now you can understand why each Image is darker or lighter than the other.
Take another look at the 3 pictures above and take note of the following: a 1/60 sec shutter speed will keep the camera shutter open about twice as long as a 1/125 sec shutter speed. On the other hand, the 1/250 sec shutter speed leaves the camera shutter open half the length of time as the 1/125 shutter speed. So now you can understand why each Image is darker or lighter than the other.
There may be times when a slow shutter speed is more desirable or necessary, especially in low light situations. A couple of situations that would require a slower shutter speed would be a fireworks display or night pictures at an amusement park. (see pictures #8 and #9) In these cases a very slow shutter speed, coupled with motion make for fun and interesting pictures.
Shutter Speed Image #8,... 3 Seconds
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Shutter Speed Image #9,... 2 Seconds
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If you are using a Digital SLR camera, like the Canon EOS Rebel T7i, you will be able to set the shutter speeds manually. You will also be able to manually set the camera shutter speed if you are using an advanced compact camera like the Sony DSCH X80 or any of the new Compact System Cameras.
All of the cameras that were just mentioned also allow you to manually set the lens aperture, ISO setting, and many other features so that you have more creative control over your pictures.
If you are using a very basic compact camera, you probably wont be able to manually adjust your shutter speed. However, basic compact cameras have automatic scene modes that can be set to match the type of scene you are photographing.
The camera will automatically set the best shutter speed for that type of scene. Please see the tutorial on Automatic Shooting Modes for a little more on that subject.
Hopefully, you now have a good understanding of the camera shutter function. Practice using the various shutter speeds to fit the situation, then add your own creativity and your pictures should be fine!