Choosing the right camera shutter speed
Camera shutter speed, usually measured in fractions of a second, combined using the size of the aperture opening, determines just how much light reaches the film or sensor. More importantly, the shutter speed setting also affects the way moving or static subjects are recorded – whether they are sharp and totally detailed, or blurred impressionistic.
Camera shutter speed basics
The biggest concern when choosing a shutter speed would be to select one which is rapid enough to prevent camera shake, caused by moving the camera during the exposure while the shutter is open.
In the event you mount your camera on a rigid tripod this really is not a problem, even for exposures lasting several seconds.
Camera shutter speed and lens As focal length increases, it becomes harder to keep the image steady, requiring a very fast shutter speed to guarantee a clear image. A 50mm calls for a speed of a minimum of 1/45 sec, a 180mm focal length needs 1/180 sec or more rapidly, and 1/350 sec is necessary for a 300mm.
When photographing a subject in motion, you are able to use the shutter speed as a way to interpret the scene. For example, when shooting a runner, a shutter speed of 1/250 or even 1/500 sec may produce a ‘frozen’, detailed image. Under the same conditions, having a shutter speed of 1/60 sec, the runner will move slightly across the lens’s field of view through the exposure. The result: still a clearly recognizable runner, but this time showing the a streaking effect that indicates movement and athleticism.
You often must consider camera shutter speed and aperture together. If, at 1/500 sec, your exposure meter indicated f4 for correct exposure, then at 1/60 sec you’d be making use of an aperture of f11, and depth of field would have elevated considerably, perhaps bringing a distracting background into focus.
Holding the camera steady
When supporting the camera with your hands alone, a common rule of thumb is the minimum shutter speed you select needs to be equivalent to the focal length of your lens. In other words, with a 100mm lens use a shutter speed of 1/100 sec or less; having a 500mm use a shutter speed of 1/500 sec or less; and so on. This relationship exists since a slight movement with a telephoto lens causes a more noticeable blurring of the image than having a wide-angle, due to the narrower angle of view and camera shutter speed.