Shutter Speed is the third out of the three cornerstones of photography, the other two being ISO and Aperture. With the shutter speed parameter one can achieve many great effects that might seem magical. Have you ever seen the picture of the freeway where there is no cars seen but just two big rivers of light -white and red – flowing together? Or you’ve probably seen how the drop of water looks in its beautiful geometrical shape before it touches the background, haven’t you? These photos are achievable due to the wizardry of the shutter speed!
Let’s take a closer look at the technical aspects of it and its application.
A camera shutter is a plate or a curtain that covers the sensor from the light and only opens when the “shutter button” is fired. On the DSLR cameras the shutter is the mirror that switches from bouncing the light to the viewfinder while keeping the sensor in the dark to the open position, revealing the sensor to the light for a certain period of time while temporarily interrupting the view of the viewfinder. The light passing through the lens aperture is being captured by the sensor with the certain sensitivity called ISO. This chain of reaction is the foundation of the art of capturing the light – the photography.
SHUTTER SPEED
Shutter speed, also known as “exposure time”, stands for the length of time a camera shutter is open to expose light into the camera sensor. If the shutter speed is fast, lets say over a 1/1000 of a second, it can help to freeze action completely, as seen with the drop of water before it hits the surface. If the shutter speed is slow, it can create an effect called “motion blur”, where moving objects appear blurred along the direction of the motion. While the example of two rivers of light flowing up and down the freeway is an instance of a very slow or “long” shutter speed (1,2,5,15 seconds), the effect of motion blur is also used very often in ads of cars and motorbikes, where a sense of speed and motion is imitated by intentionally blurring the spinning wheels.
Also the landscape photographers intentionally use slow shutter speeds to create a sense of motion on rivers and waterfalls, while keeping everything else in focus.
Shutter speeds are typically measured in fractions of a second, when they are under a second. For example 1/2 means a half of a second, while 1/150 means one one-hundred-and-fiftieth of a second. Most modern DSLRs and mirrorless cameras can handle shutter speeds of up to 1/8000th of a second and faster. The longest shutter speed on most cameras is typically 30 seconds. There is also a bulb mode where the shutter speed is as big as the period of pressing the shutter button.
Fast shutter speed does not have a set number. It is what it takes to freeze the action of the subject. For people the 1/250 might be more than enough, for birds 1/1000 is a good number to start with.
Slow shutter speed is also a relative term. It is what it takes to capture the motion without introducing the blur or a camera shake. Some lenses, however, aid to avoid the shake by having an image stabilization or “vibration reduction” technologies installed within lens.
And long shutter speeds are typically above 1 second, when you have to use a tripod to get acceptably sharp images (for low-light/night photography or to capture movement).
SETTING THE SHUTTER SPEED
Most cameras handle shutter speeds automatically through in-camera metering. When the camera is set to “Auto” mode, both shutter speed and aperture are automatically selected by the camera. When you shoot in “Aperture Priority” mode, you set the lens aperture, while the camera automatically sets the shutter speed.
On the other hand, setting the camera to “Shutter Priority” lets you control the shutter speed while the camera takes care of the aperture.
Also the “Manual” mode is a complete autopilot OFF mode where you get to control and set all parameters manually (duh?).
It is a common practice to leave the camera on “aperture priority” and have the camera control the shutter speed.
Take a look at the video below posted by Apalapse that explains the Shutter Speed in a very easy to grasp way!