One of the fundamental exposure controls is shutter speed. This setting determines the duration of the exposure, while the aperture (or ƒ-stop) determines the amount of light that’s let into the camera. Together, they pair with the ISO to comprise the exposure.
Shutter speed is especially important when it comes to the sharpness of a photograph in several ways. Unless the camera is mounted to a tripod (in which case the shutter speed can be much slower) the first task of shutter speed is to produce an exposure that eliminates any shake or subtle movements from the photographer’s hands.
When I was learning the basics of shutter speed as a student wielding an old manual 35mm SLR, the rule of thumb we were taught was to never handhold a camera at a shutter speed slower than 1/60th of a second. This serves a photographer well so long as she’s using a normal lens in the 50mm range or a lens shorter/wider than that. The reason, in fact, reveals the actual rule of thumb we should use to ensure sharp pictures when handholding: Always use a shutter speed faster than the focal length of the lens.
In the case of a 50mm prime, then, the slowest shutter speed one should handhold with is 1/50th of a second. In the manual film camera days, the options around 1/50th were just 1/60th or 1/30th, making 1/60th the safe minimum choice for handholding. Thus, that oft-quoted, though slightly errant, rule of thumb.
If a photographer is using a long telephoto lens, such as a 200mm prime, the scene is magnified. This also serves to magnify every little movement of the camera, which is why it gets trickier to steadily handhold a lens the longer it gets. With that 200mm lens in hand, a photographer should use a shutter speed of 1/200th or faster to eliminate camera shake. An ultralong 600mm supertelephoto requires an even faster shutter speed of at least 1/600th, while a wide lens such as a 20mm prime can get away with a slower shutter speed, as the wide angle of view minimizes shake. In any case, the shutter-speed-to-focal-length rule of thumb holds true for producing reliably sharp photos.
Just because the shutter speed is fast enough to eliminate typical blur caused by a photographer’s unsteady hands doesn’t mean it will render the subject perfectly sharp. Obviously fast-moving subjects require faster shutter speeds, but so do slow-moving subjects—even when photographing something as relatively calm as people standing still.
Even when a person is just sitting or standing, they’re not stock-still. They move, and that movement requires a faster shutter speed to ensure the elimination of motion blur. A cooperative subject trying to hold still may come through sharply at 1/60th of a second, but I find 1/125th to be a much more reasonable “bare minimum” of shutter speed to ensure humans are sharp in most normal portrait circumstances. And when I’m working quickly or photographing subjects that may be walking, talking or gesturing, I use 1/250th as the minimum safe shutter speed for sharp subjects. It’s because the last thing I want is for a little bit of motion blur to ruin an otherwise perfect shot—especially when it’s so relatively simple to ensure. If I’m handholding at 1/250th, it takes a fast-moving subject to make a blurry photo.
Speaking of fast-moving subjects, never is this more evident than when photographing sports. It doesn’t have to be fast-moving race cars or bicycles to require really fast shutter speeds (such as 1/1000th or faster). Sports with people running and jumping, such as baseball, basketball, tennis, football, soccer and gymnastics, all require a very fast minimum shutter speed. In my experience, 1/1000th is the slowest shutter speed at which I’m comfortable photographing most sports, and I’m going to aim for 1/2000th if the lighting will allow it.
When Blur Is Good
One instance in which I may actually choose a slow shutter speed with a fast-moving subject is when I want to deliberately create motion blur to add to the feeling of motion in a scene. Sometimes a tack-sharp photo of an athlete in motion, for instance, doesn’t convey the feeling of speed or movement that an intentionally blurry photograph does. The technique most often employed to deliberately add motion to a moving subject is called panning.
To do it, experiment with slower shutter speeds while moving the camera with the subject, trying to keep the subject centered in the frame during the move. This will produce a subject that’s mostly sharp while introducing streaks of blur in the stationary objects in the background, as well as blurring any moving parts on the subject—such as running legs. The same shutter speed held still while a moving subject transits the frame would produce a sharp background and a blurry subject. Both approaches can be viable to introduce deliberate motion blur to a scene with a moving subject.
This piece began with a rule of thumb regarding minimum shutter speeds for handheld photographs. There’s one technological aid that changes this equation, and that’s the use of optical image stabilization (also called vibration reduction) to help stabilize the lens and/or camera sensor in order to eliminate shake and produce sharper photographs.
For years, I considered vibration reduction as a way to add perhaps a single stop of handholdability—meaning instead of needing a shutter speed of 1/125th I could actually get away with using 1/60th. I’ve long been somewhat skeptical of manufacturer claims regarding just how much steadying optical image stabilization can provide, but a recent experience proved to me just how tremendous this technology can be. Check out the screenshot above.
It’s an enlargement of a portrait shot with an 85mm lens, handheld with a much-too-slow shutter speed of 1/15th of a second. Notice that the details are absolutely tack sharp—way sharper than would typically be attainable when handholding a portrait lens at such a slow shutter speed. I don’t advise handholding at 1/15th, but it’s good to see how much steadier our photographs can be with the aid of image stabilization.