Shutter speed is measured in seconds, and a fast shutter speed is one that is shorter in duration. For instance, a shutter speed of 1 second is twice as fast as a shutter set to 2 seconds. And whilst we can agree that a shutter speed of 1/2000th of a second sounds pretty fast, there will be occasions when it’s not fast enough.
Therefore, it’s useful to consider fast and slow shutter speeds as terms relative to what you are trying to photograph. And your goal as a photographer is to use a speed that is neither too fast nor too slow but just right. So, with that in mind, here are 3 reasons why you might choose to use a fast shutter speed. Jump to Conclusion
When to use a fast shutter speed
There are 3 reasons why you would choose to use faster shutter speeds.
- Your photo is too bright and you need to reduce the amount of light your camera’s sensor/film is exposed to.
- You wish to take a sharp photo of a moving subject.
- You want to prvent the movement in your hands shaking your camera and blurring your photo.
1. Your photo is too bright!
Your photo will appear excessively bright if you expose your camera’s sensor/film to too much light. However, you can reduce the amount of light your camera receives by using a faster shutter speed. Read Ultimate Guide to Shutter Speed.
For instance, halving your shutter speed from 2 seconds to 1 will half the amount of light entering your camera. As a result, your photo will appear half as bright.
The following image illustrates the effect shutter speed has on your photo’s brightness.
2. Using a fast shutter speed to avoid motion blur
To capture a sharp photo of a moving subject such as a bird or family member, you must use faster shutter speeds.
For example, let’s say you are taking a photo of your son running at 10mph. At 10mph, we can expect your son to cover a distance of about 150 inches per second (about 4 meters).
Therefore, if you took your photo with your camera’s shutter set to 1/50th of a second, your Son will appear blurred since he travelled nearly 3 inches throughout the exposure. Or, to put it another way, your son’s movement has smudged him across your photo.
But, set your shutter to 1/2000th of a second, your Son will have barely traveled a millimeter and appear sharp as a result. Read How to Take Sharp Photos.
Yet, on occasions, you may wish to use slower shutter speeds to deliberately induce motion blur. Waterfalls are a good example of this technique.
3. Using a fast shutter speed to avoid camera shake
If your shutter speed is too slow, the natural, involuntary movement in your hands shakes your camera and blurs your whole photo. By using faster shutter speeds, camera shake can be prevented.
Although it varies between individuals, the slowest speed you should use for handheld photography is about 1/Focal Length. If, for example, you are using a 50mm lens, the slowest speed you should use is 1/50th of a second.
For more information, Read Avoiding Camera Shake with the Reciprocal Rule
The challenge of using faster shutter speeds
The faster your shutter speed, the less time you camera’s sensor or film has to absorb light from the scene. This can be particularly difficult if a low-light scene demands a slower speed yet a fast moving subject demands a faster speed.
In this situation, the answer is to increase your camera’s supply of light by using a larger lens aperture. Apertures come in different sizes and larger your aperture is, the more light your camera will receive during any given moment. For instance, an aperture of F4 provides twice as much light as an aperture set to F5.6.
To find out more about aperture, read What is Aperture.
You final option is to increase your camera’s ISO. ISO does not contribute additional light. Instead, it artificially boosts your photo’s brightness. Although ISO is incredibly useful, using it degrades the quality of your photos. Therefore, ISO should be considered a last resort. Read about ISO.
A fast shutter speed is simply one which is shorter in duration. For instance, a 1 second shutter speed is twice as fast as a 2 second one. However, the difference between too fast and too slow is a matter of requirement.
Therefore, your ideal shutter speed is one that supplies your camera enough light to produce a sufficiently bright photo. However, you may need to use even faster speeds if you need to capture a sharp photo of a moving subject, or to prevent your hand’s natural wobble shaking the camera and blurring your photo.