Shutter speed is part of the exposure triangle along with aperture and ISO. Shutter speed doesn’t only control the exposure but also lets the creative photographer to innovate and experiment with the motion. When understood to the core, shutter speed is not a technical but a creative tool.
The Shutter as an Essential Part of the Camera
The shutter is the part of the camera that remains closed to prevent light from entering and reaching (exposing) the sensor. When the shutter button is pressed, the shutter curtain opens to let light reach the sensor. The sensor records the intensity of light while the shutter is open; this is how the image is formed.
Without the shutter mechanism, the sensor stays exposed and there is no way to eliminate the light other than manually blocking it with your hand or a card, which was a common practice in early photography.
Definition of Shutter Speed
Shutter speed is defined as the time duration between the opening and closing of the camera shutter. It is the time that the sensor or film records the light and, hence, creates a photograph.
How Shutter Speed is Measured
In most cases, shutter speed is measured in fractions of seconds. However, some long exposure images require a shutter speed of up to 30 seconds or longer.
Shutter speed is usually measured as follows:
1/2000s, 1/1000s, 1/500s, 1/250s, 1/125s, 1/60s, 1/30s, and so on.
Each stop down the line (from 1/60s to 1/30s, for example) increases the duration of time the shutter stays open by a factor of two and, as a result, doubles the amount of light that reaches the camera sensor.
Shutter Speed: 1/13s
The Shake Blur
Often times, shake blur happens due to shake or movement in the camera while the shutter is still open. It can be avoided by using a tripod with a remote shutter release/timer or the minimum shutter speed rule. If you ever wondered why your photos appear blurry or soft, it is because of those slight movements while the shutter was open.
The Minimum Shutter Speed Rule for Shake-Free Photos
When not using a tripod or another type of support, photos tend to have ‘shake blur’ if the shutter speed falls below a particular number. This has been calculated and is given as:
1/focal length or 1/100, whichever is faster
Therefore, if you are using a full-frame camera with an 85mm lens, the minimum shutter speed you need to keep is 1/100 (because 1/100 is faster than 1/85). However, if you are using the same camera with a 300mm lens, the minimum shutter speed is 1/300.
On a crop frame sensor, multiply it with the crop factor. For example, an APS-C sensor camera with the same 85mm requires that you use a minimum shutter speed of 1/(85 x 1.5) = 1/127.5. Here, you will use 1/150 and not 1/125 to avoid any chance of shake.
If your lens has an image stabilization feature, you can reduce it by that many stops from the minimum shutter speed. For example, if you have to use a minimum shutter speed of 1/125, but your lens has a 1 stop IS, you can use a shutter speed of 1/60.
Shutter Speed: 1/6s
Freeze the Moment or Faster Shutter Speeds
Faster shutter speeds tend to freeze the moment, which is commonly used for wildlife photography and water splash photography among many others. A bird in flight may require you to shoot at 1/2000 or faster. Freezing the motion of water may require you to shoot at 1/1000 or faster depending on the flow of water. This technique is also used in action shots.
For example, freezing the motion during racing events can produce tack sharp pictures with tiny bits of dirt frozen mid-air as they splatter across the tires.
Creative Motion Blur or Slower Shutter Speeds
Slower shutter speeds tend to produce motion blur. This is achieved by keeping a major part of the subject, or at least some part of subject, still while the moving parts are naturally blurred in motion. This technique is common in shooting light trails and creative dance movements. Star trail photography is based on the motion blur of the stars and their movement.
Shooting landscapes that feature water also involves blurring the motion to make the water appear silky smooth. Many photographers do this when shooting waterfalls to imitate the style used in paintings.
When using extended exposure times, this is commonly known as long exposure photography. Star trails, nightscapes, and Milky Way photography are grouped in this category. Typically, the shutter speed is very slow, which makes it impossible to shoot without a sturdy support like a tripod.
Shutter Speed: 2.5s
Setting the Shutter Speed – Two Major Modes
Shutter priority mode lets you set the shutter speed while the camera automatically sets the aperture based on the light conditions, metering mode, exposure compensation, and locked-in ISO settings. In manual mode, all the settings are completely manual including the shutter speed and aperture; metering only offers a guideline for the correct exposure.
Where Can You Find the Shutter Speed?
The shutter speed can be found on the bottom left of the viewfinder screen or on the top of the camera’s LCD panel (not all cameras have this feature). Also, you can find the settings displayed on the camera’s rear LCD screen. Shutter speed is usually denoted as a number instead of fractions. For example, 1/125 is denoted as 125, and 1 second is denoted as 1. However, this convention has changed in a few recent camera models.
Aperture helps us control the depth of field, while the shutter speed lets us control the flow of the image. Whether you want to freeze the motion, use creative blur, or stack star trails, the shutter speed gives wings to your creativity. Timing is also of great importance because pressing the shutter button at the right time with the correct settings can produce incredibly stunning results.