The Beginner’s Guide To Shutter Speed
A photograph is a single moment in time. The shutter speed determines just how long that moment is, whether a few seconds, or just a fraction of a second. Any time a camera’s shutter is open, an image is being taken. It’s the shutter speed that determines just how long the shutter stays open. Understanding shutter speed is essential to mastering manual modes and taking complete control over your images.
What is shutter speed?
The camera’s shutter is what opens to let light in to take the image. Shutter speed isn’t necessarily how fast the shutter opens and closes, but how long it stays open, or the duration.
Since the camera’s shutter lets in light, a slow shutter speed lets in more light, while a short shutter speed lets in just a little. Of course, that means shutter speed has an impact on the exposure. In low lighting, a slower shutter speed is often necessary to let in enough light, or you’re left with a dark image.
Shutter speed is measured in seconds, or fractions of seconds. A very slow shutter speed will be a few seconds long. This is referred to as a long exposure. Fast shutter speeds are just a fraction of a second, like 1/8,000. Most cameras also have a bulb mode, which simply means the shutter stays open until the photographer presses the shutter release again. Bulb mode is helpful for when it’s unclear how long the shutter speed needs to be, or when the minimum shutter speed on the camera isn’t slow enough.
Shutter speed usually doubles from one setting to the next, so the available shutter speeds look a little like this (with the “ mark often used to designate seconds) :
Outdoors during the day, choosing a fast enough shutter speed isn’t usually a problem. Shooting indoors or at the end of the day, however, becomes a challenge. Since fast shutter speeds let in less light, a wider aperture or a higher ISO is necessary.
Shutter speed and blur
Anything that moves while the shutter is open results in blur. That’s why fast moving action requires a fast shutter speed. If the shutter speed is too slow, the subject will be blurry.
This simple concept, however, can be used in a number of different ways. Along with preventing blur, shutter speed can also be used for intentional blur. A long exposure with a slow shutter speed is often used to intentionally blur a subject. At slow shutter speeds, waterfalls become smooth, moving traffic becomes streaks of light and people become a busy blur. Long exposures are often used to convey motion within a single image.
Shutter speed is also essential to mastering techniques like panning and zoom burst. If you use a slower shutter speed, like a 1/60, then follow the action in a panning motion as the shutter is open, the subject will be clear, while the background will be blurred from the motion. In a zoom burst, using a slow shutter speed, like two seconds, and zooming while the image is being taken results in a blur that radiates towards the center of the image.
Shutter speed and camera shake
A slow shutter speed can also blur the entire image if the camera moves just slightly in your hands. A tripod helps prevent this by keeping the camera steady during the exposure. Image stabilisation also helps enable photographers to use a shutter speed that’s slow by a step or two, compared to using gear that’s not equipped with image stabilisation.
But how do you know if your shutter speed is enough to keep the camera handheld, or if you should use a tripod? Since telephoto lenses also enhance the effects of camera shake, the answer depends on what focal length you are using. As a general guideline, turn the focal length of your lens into a fraction: A 200mm telephoto becomes a 1/200, for example. So, if you are zoomed into 200mm, you should use a shutter speed of 1/200 seconds or faster. Camera shake is less intense on shorter lenses, so if you’re using your 55mm kit lens, you can get away with a 1/60 second shutter speed.
Shutter speed and flash
When adjusting the aperture and ISO isn’t enough to get a fast shutter speed with the proper exposure, a flash can help, but that’s not always the case. The flash often can’t keep up with fast shutter speeds. A camera’s flash sync speed indicates the fastest shutter speed that can be used with the flash on. On most DSLRs, the flash sync speed is 1/200 or 1/250.
Thankfully, the characteristics of the flash helps to freeze motion. In many cases where a 1/250 would be too slow, using the flash at 1/250 will often capture the shot without blur, even though without the flash at the same speed, there would be blur.
How to set shutter speed on a DSLR
Shutter speed can be set in either shutter priority mode, where you only choose the shutter speed, or full manual, where you choose shutter speed as well as the aperture and ISO.
On most DSLRs, the shutter speed isn’t displayed as a fraction (probably to preserve space), so 1/200 is written as 200. To see if that number is a fraction or a second, the “ symbol is used with shutter speeds of a second or longer, like 1” and 1.3”. If your DSLR has a second screen at the top of the camera, the shutter speed is usually displayed next to the aperture, or the number with an f in front of it. The shutter speed is also displayed when the shooting settings are on the LCD screen, and also at the bottom of the viewfinder, again, normally next to the aperture of f-number.
On most DSLRs, the control wheel that rests near your thumb adjusts the shutter speed. Try that dial and watch the numbers change. Some cameras with a single control dial use a function button to switch between adjusting shutter speed and aperture.
Like many aspects of photography, understanding shutter speed is best done with a bit of practice. Head out to someplace with plenty of moving subjects, like a racetrack, a local team’s match or a park. Use shutter priority mode (the S or Tv on the mode dial) and experiment with different shutter speeds to see, hands-on, what the different settings produce. Keep in mind the speed of the subject plays a role too, and try to match the shutter speed with the subject. How low can you get before the subject appears blurry? How low can you get before you notice some camera shake?
As one of the three elements of exposure, understanding shutter speed is essential to taking complete creative control over your photography.
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