Choose the Right Shutter Speed

You must choose a shutter speed that stills both camera and subject movement. If using a tripod, a shutter speed of 1/15 to 1/60 second should be adequate to stop average subject movement. Outdoors, you should normally choose a shutter speed faster than 1/60 second, because even a slight breeze will cause the subject’s hair to flutter, producing motion during the moment of exposure. If you are using electronic flash, you are locked into the flash-sync speed your camera calls for unless you are dragging the shutter (working at a slower-than-flash-sync shutter speed to bring up the level of the ambient light).

When handholding the camera, you should select a shutter speed that is the reciprocal of the focal length of the lens you are using (or faster). For example, if using a 100mm lens, use 1/100 second (or the next highest equivalent shutter speed, like 1/125) under average conditions. Some photographers are able to handhold their cameras for impossibly long exposures, like 1/4 or 1/2 second. To do this, you must practice good breathing and shooting techniques.With the handheld camera laid flat in the palm of your hand and your elbows in against your body, take a deep breath and hold it. Do not exhale until you’ve squeezed the shutter. Spread your feet like a tripod and if you are near a doorway, lean against it for additional support.

If you are shooting handheld and working very close to the subjects, as you might be when making a portrait of a couple, you will need to use a faster shutter speed because of the increased image magnification. When working farther away from the subject, you can revert to the shutter speed that is the reciprocal of your lens’s focal length. When shooting subjects in motion, use a faster shutter speed and a wider lens aperture. In this kind of shot, it’s more important to freeze subject movement than it is to have great depth of field. Ultimately, if you have any question as to which speed to use, use the next fastest speed to ensure sharpness.

A great technical improvement is the development of image stabilization lenses, which correct for camera movement and allow you to shoot handheld with long lenses and slower shutter speeds. Canon and Nikon, two companies that currently offer this feature in some of their lenses, offer a wide variety of zooms and long focal length lenses with image stabilization. If using a zoom, for instance, which has a maximum aperture of f/4, you can shoot handheld wide open in subdued light at 1/10 or 1/15 second and get dramatically sharp results. This means that you can use the natural light longer into the day while still shooting at low ISO settings for fine grain.
It is important to note, however, that subject movement will not be quelled with these lenses, only camera movement.