Freezing Motion with High Shutter Speed
Between aperture and shutter speed, aperture is usually the control that people use creatively, while the shutter speed is the workhorse of the two. But in reality, you can use shutter speed to freeze and convey motion. For this first part on shutter speed, we will be focusing on how to improve your fast shutter speed technique to freeze motion.
© Pete Henze (PeteHenze@gmail.com)
When it comes to modern cameras and its range of shutter speed, it seems that freezing a moving subject should be pretty easy. But if you remember from our Exposure Guide, if you use a high shutter speed, you will need a wider aperture or higher ISO in order to balance out the exposure, and sometimes you may be limited with your aperture and ISO choices. Therefore, it’s good to know what the minimum shutter speed that you can use if you want to freeze a subject in motion. Here are three components that affects your minimum shutter speed options:
The most influential factor when it comes to freezing motion is the speed and direction of the moving subject. If the motion is slow, like someone waving his hand, you probably can freeze that motion with a 1/100th second shutter speed. But if the speed of the motion is fast, like someone swinging a baseball bat, you may need 1/1000th second to freeze the action.
When it comes to direction, a subject that is moving towards you or away from you can be frozen with a slower shutter speed than a subject that is moving in a side-to-side direction. So, if you want to freeze a dog running towards you, you can probably freeze it with 1/500th second shutter speed, whereas if the dog is running right to left, you may have to increase the shutter speed to 1/800th second. This is because the motion is more pronounced when the subject is moving across the frame as opposed to towards or away from you.
When the subject is close to you, the range of motion across the frame is much larger than when the subject is farther away from you. As a result, when you are shooting a moving subject up close, your shutter speed needs to be higher than when you are shooting the same subject moving the same speed a lot farther away.
An example of this would be if someone was bouncing a basketball 5 feet from you versus someone bouncing a basketball at the far end of the basketball court.
The lens focal length that you are shooting with and how much of the frame your subject is occupying also affects how fast of a shutter speed that you will need. A wide angle lens requires less of a shutter speed to freeze motion as opposed to a telephoto lens. Just like shooting a subject that is up close, when you zoom in with your lens or use a telephoto lens, the subject’s size and motion in the frame becomes more pronounced.
If you are shooting a soccer match with a wide angle lens, each player is moving through a small space of the frame. If you zoom in or use a telephoto lens, you will need a faster shutter speed in comparison to when you are using a wide angle lens.
Although these two factors are not directly related to shutter speed, focus and shutter lag do play a key role when it comes to shooting fast moving subjects.
Your camera’s autofocus speed and continuous autofocus (AF) capability affects whether you can catch your moving subject in focus or not. Some cameras like the Canon 7D, Canon 5D mkIII and the Nikon D800 are great at locking in a moving subject and keeping track of them as they move through a 3-dimensional space.
Mirrorless cameras such as the Sony NEX-7 and the Olympus OM-D have made significant advances with their autofocus system. For still and slower moving subjects, their focus is spot on and can be just as reliable as the traditional DSLRs. For fast moving subjects like football players, however, the mirrorless cameras’ continuous AF speed and accuracy still lags behind the DSLR cameras.
Shutter lag is the split-second delay between the time you hit the shutter button and the time the sensor actually records the photo. Two reasons for shutter lag are the camera trying to autofocus and the camera flipping the reflex mirror out of the way of the sensor.
If you are shooting something really fast, like a horse race, then you have to be prepared for both the focus lag and shutter lag. No sense on just catching a crisp photo of the rear half of the horse. Try pre-focusing for the area of the race track where you think the subject is going to pass through in order to minimize shutter lag.
Whenever you are faced with a moving subject and you want to freeze the motion, you can increase the shutter speed. Although, we provide the suggested minimum shutter speed for different scenarios if you can use a faster shutter speed and compensate the exposure with aperture or ISO, then use it.
Finally, while it is great to have the capability to freeze motion, you don’t have to use it all the time. Part of the fun about photography is making the creative choices such as whether you want to freeze motion with a high shutter speed or convey motion with a slow shutter speed.
In our next guide, we will be talking more about how to use slow shutter speed creatively.