Shutter speed is one of the most exciting aspects of photography because it can help you capture motion, or freeze high-speed actions in your images. It's a concept that may sound a bit complicated at first, but once you see it and its effects, it can be easy to put in practice.
What is Shutter Speed?
In simple terms, shutter speed refers to the length of time that the camera's shutter remains open to expose the camera sensor to light. It's measured in seconds or fractions of a second, such as 1/1000 or 1/60. The faster the shutter speed, the shorter the amount of time the shutter remains open, and the less light enters the camera. In many cameras the shutter is a physical cover that prevents light from reaching the digital sensor (or film). When the photograph is taken, the shutter moves and exposes the sensor/film to the light coming into the camera. It returns to cut off the light in a set amount of time, known as shutter speed. There are more advanced concepts that involve mechanical vs electronic shutters, rolling shutter, and shutter speed vs frame rate but, for the time being, we will stick with the basics.
Freezing Motion with Fast Shutter Speeds
A particularly useful thing about shutter speed is that you can use it to freeze motion in your images. For example, if you're photographing a person running, a fast shutter speed of 1/1000th of a second or faster can freeze their movement and create a sharp image. Similarly, if you're photographing a bird in flight, a fast shutter speed can freeze their wings in motion and create an image rich in detail that otherwise would have been blurry. Fast shutter speeds are used often in scientific research in order to capture natural phenomena which happen at speeds too fast for the human eye.
Capturing this surfer and the wave breaking in great detail requires a fast shutter speed.
Creating Motion Blur with Slow Shutter Speeds
On the other hand, you can also use slow shutter speeds to create motion blur in your images. This technique is often used in landscape photography to create a sense of movement in waterfalls, rivers, and clouds. To achieve this effect, you'll need to use a tripod or another stable surface to keep your camera steady while the shutter remains open for several seconds. If you've ever seen photographs with traffic headlight/taillight blurs along busy roads, you can guarantee that the photographer was using a slow shutter speed.
This photograph highlights the movement of the water using a slow shutter speed and motion blur.
Using Shutter Speed to Control Exposure
Shutter speed also plays a crucial role in exposure, which refers to the amount of light that enters the camera to create an image. In bright conditions, you may need to use a fast shutter speed to limit the amount of light entering the camera and prevent overexposure. Conversely, in low-light conditions, you may need to use a slower shutter speed to allow more light into the camera and achieve proper exposure. In astrophotography, in particular, you have to balance the need to let in as much light as possible (slower shutter speed) with the need for a sharp image (too slow and you will capture the stars creating trails as the Earth spins... unless that's what you want - see above point about motion blur :D). In bright light situations where you want to capture motion blur, narrowing your aperture and/or using a dark filter (like sunglasses for your camera) lets you slow down your shutter speed.
This photographer was clever in using a slower shutter speed to capture the faint light of the stars as well as the motion blur of water beneath.
Conclusion
Shutter speed is a fun and exciting aspect of photography that can help you freeze or blur motion in your images. By adjusting the shutter speed, you can create stunning images of fast-moving subjects, capture the motion of a waterfall or river, and control exposure in different lighting conditions. So grab your camera, experiment with different shutter speeds, and have fun capturing the world around you!