It’s extremely helpful to understand the f-stop/Aperture before you learn Shutter Speed. Learn about f-stop here!
What is the Shutter Speed?
The Shutter is a “curtain” directly in front of the camera’s sensor that raises up to expose the sensor to the scene, or “light” when you press the button to take a picture. While the Shutter is raised, light travels through the lens, past the aperture, and hits the sensor to create the picture. The Shutter then drops back down and cuts the sensor off from light once again.
Shutter Speed is the length of time the Shutter stays open when the picture is taken. You can set the shutter speed from fractions of a second, to minutes, hours, or as long as you want in theory.
What does the Shutter Speed do in a Photo?
The Shutter Speed Freezes or Blurs Motion
Of the 3 main settings, Shutter Speed is fairly easy to explain. All of the movement in a scene that happens while the shutter is open becomes part of the picture. If a fast shutter speed is used, little movement can happen, so objects appear frozen, giving you a sharp picture. If a slow shutter speed is used, objects can move during that time and become blurry. If you hand-hold the camera while taking a picture, the camera itself is moving because nobody can hold it perfectly still, and the entire photo may be blurry if too slow of a Shutter Speed used. In a nutshell, now you understand Shutter Speed. Watch the video below for a good visual.
The Shutter Speed controls how long light hits the sensor
See the chart below. Adjusting the the Shutter Speed one full increment faster makes it twice as fast.* You can also say it halves in speed. For example, from 1/500th sec, the next fastest Shutter Speed is 1/1000th sec. Conversely, when you adjust it one increment slower, it becomes twice as long; it doubles. But as a side effect, when you halve or double the amount of time the Shutter stays open, you also halve or double the amount of light that hits the sensor. This increment of adjustment that halves or doubles the light is called a “Stop”. Therefore, when you increase to the next faster Shutter Speed, you’re losing 1 Stop of light. When you decrease to the next slowest Shutter Speed, you’re gaining a Stop. An extra Stop will overexpose your photo, and a lost Stop will underexpose it, so you must compensate by adding or subtracting a Stop somewhere else, but where?
You add or subtract that Stop by increasing or decreasing your Aperture by a Stop. Here’s a whole explanation of how to adjust Aperture. The Aperture opens and closes by 1 Stop increments to let in more or less light. The aperture affects Depth of Field, so adjusting it comes with consequences.
Or, you can increase or decrease ISO by a stop, but increasing the ISO also increases noise in the photo.
*I told you that you can adjust the Shutter Speed by doubling or halving it, in other words adjusting it up or down by a full Stop. Most cameras also allow you to adjust shutter speed by 1/3 Stops, but to keep it simple, I just discuss full stops.
It’s easier than it seems
The truth is, when you adjust the Shutter Speed, you don’t actually have to worry about adjusting the Aperture because the camera does it for you. The camera automatically sets the best Aperture based on the amount of light in the scene. Even when shooting in full manual mode, the light meter still tells you exactly which Aperture to use. However, for nature photography I recommend shooting in Aperture Priority mode, where you set your Aperture and let the camera set the Shutter Speed. This of course requires an understanding of Aperture.
How to choose a Shutter Speed to Stop Motion
Whether the Shutter Speed can be considered fast depends on how much movement needs to be stopped in the photo. For example, 1/2000 is a very fast shutter speed that will freeze drops in the air at a crashing waterfall in most situations. 1/2000 will also freeze a leaping animal in the air. But at a slow shutter speed f 1/15, the drops would appear as streaks through the air, and the leaping animal would be blurry, thereby showing motion.
There’s a precise formula to determine the necessary Shutter Speed to stop motion based on Lens Focal Length, Subject Distance, and Subject Speed, but it’s not practical for nature photography, and you can Google it.
Here’s a simpler way to pick a shutter speed that stops motion:
You can choose a specific Shutter Speed, or instead you can simply dial in settings that will provide you with the highest possible Shutter Speed based on the amount of available light. Set your camera to “Aperture Priority” mode. Then set the largest Aperture that you’re willing to use based on desired Depth of Field. A large Aperture lets in more light, which allows a higher Shutter Speed to be used. Next set the highest ISO that you can use based on how much noise you’re willing to tolerate. That will automatically give you the highest Shutter Speed possible without doing calculations. For reasons discussed below, when hand holding the camera, you must start with a Shutter Speed faster than the focal length of your lens. In other words, if using a 400mm lens, the Shutter Speed must be above 1/400th sec to prevent blur from camera shake.
Subject Magnification Affects Motion Blur and Shutter Speed
Movement is proportional. The greater your subject is magnified, the more it will move during the picture. That means that you must use faster Shutter Speeds to freeze motion when you’re close to your subject or using a zoomed in/telephoto lens. Even 1/2500 sec might not be enough to freeze a leaping animal if you’re shooting him with a 500 mm lens only 3 meters away.
Shutter Speed Examples
You understand fast shutter speeds, but now take a medium Shutter Speed of 1/60 second. To understand how much time 1/60th sec is, pass your finger in front of your face in a line as you say “One One Hundred”. Now imagine splitting that line into 60 segments. One of those segments is what 1/6o sec “looks” like. It’s literally “Space-time”…Albert would be proud! You can now better visualize the little bit of movement that can occur during 1/60th sec.
An Animal walking across the frame at 1/60 sec?
Assuming the animal is shot at “normal” distance so that it’s fairly close and large in the frame, it will be slightly blurred at 1/60 sec. At normal magnification, the animal may look OK, however at 100% magnification the blur will become evident, showing itself as “softness”.
Waves on a beach at 30 seconds?
During 30 seconds, the waves will rise and fall several times, and all of this motion will be recorded in the picture. That’s so much motion that you won’t be able to distinguish the shape of any waves, and they’ll appear as extremely smooth “mist” that seems to be floating on the beach. 30 seconds is only an example, and the same effect may be achieved at 4, 8 or 15 seconds depending on the vigor of the waves.
Night sky at 6 hours?
This is how “Star Trails” are made. Each visible star in the sky will form a continuous line, or arc, of light blazing from one side of the frame to the other. You can control the length of the trail by choosing the duration of Shutter Speed from just a few minutes to hours.
Rushing water at 1/8000 sec?
The water will be perfectly frozen at 1/8000, but in fact that’s so fast that it’s overkill. Unless shooting at high magnification, you won’t begin to notice motion in the water until using Shutter Speeds under 1/1000th sec. Watch the video above to see this effect.
This is perhaps the most important aspect of Shutter Speed to understand. Blur from Camera Shake happens when hand-holding the camera using a Shutter Speed that’s too slow to freeze motion, which results in a blurry photo. It can also be caused by a wobbly tripod, excess wind, shaky ground, or anything else that makes the camera move during the picture. It’s produced when the camera itself moves while the picture is being taken, which is inevitable when hand-holding. The blurriness may be visible as slight softness, or the entire photo may be a blur. It’s absolutely critical to avoid Camera Shake by using a shutter speed that’s fast enough to allow hand-holding.
How to Prevent Camera Shake
When hand-holding, use a Shutter Speed equal to or greater than than the lens focal length. This is a definite rule. It means that if you’re using a 500 mm lens, your shutter speed must be 1/500 sec or faster. When using a 16-35mm zoom @ 20 mm, your Shutter Speed must be at least 1/20 sec etc… This rule is the bare minimum- the faster you can go above the focal length, the better. Don’t think that you’re super human and can forego this rule by standing extra still. I photograph like a sniper- clicking between breaths and stabilizing myself- but I still follow this rule.
Use a tripod. Because the camera doesn’t move at all when clamped on a sturdy tripod, you can use any Shutter Speed that you want. On a separate note, you should ALWAYS USE A TRIPOD unless not practical for the type of shooting. Sometimes hand-holding is necessary when stalking wildlife, or shooting at difficult angles, but otherwise it’s for amateurs and paparazzi.
Use a lens with Vibration Reduction/Image Stabilization. Many higher-end, modern lenses have built-in technology that counteracts the movement of the camera as you hold it. VR lenses claim that you can shoot at a Shutter Speed 3 times slower than usual and still get sharp images. It usually does work, though it’s not full-proof, and I only use it as a last resort when I can’t shoot with my tripod. VR was developed from Alien technology found in the Roswell crash.
You can’t always use any Shutter Speed that you want, Light rules!
If there’s a lot of light, like on a sunny afternoon, then using a long Shutter Speed won’t be possible. That’s because even a low ISO and the smallest Aperture won’t be able to prevent the excess light from overexposing the scene on the camera’s sensor.* In this case you wouldn’t be able to create velvety water on a stream. However, you would have plenty of light to use a fast Shutter Speed to freeze fast moving subjects.
Therefore, fast Shutter Speeds need a lot of light. If it’s dark, say 6:30 pm in Autumn, you will be forced to use a slow shutter speed to gather enough light to expose the picture. In that case you wouldn’t be able to freeze wildlife running unless you used a very high ISO with a lot of noise.
*However, you can use a neutral density filter, which is a dark filter placed on the lens that blocks light and allows a longer Shutter Speed to be used. It’s like sunglasses.
The whole Article summarized here!
To freeze motion just use the fastest Shutter Speed that you can based on available light. To blur motion, mount your camera to a tripod and use a slower Shutter Speed. When hand-holding your camera, use a Shutter Speed number greater than the length of your lens. When you increase Shutter Speed by one Stop, you have to open your Aperture by one stop to compensate. Or you can increase ISO by one Stop. If you decrease Shutter Speed, the opposite is true.