Exposure and Lighting For Digital Photographers Only

Chapter 6. CONTROLLING MOTION WITH SHUTTER SPEED

Shutter speed is the exposure element that controls how long your camera's sensor is exposed to light. It's the time-based factor of exposure, and as such, it becomes the critical exposure element when you must control motion in a photograph.

Note

See Chapter 5 for an overview of the relationships between shutter speed, aperture, and sensitivity.

Figure 6-1. 

Most photographers think of shutter speed primarily in terms of freezing subject motion, such as that of the horse and rider in figure 6-1. That's an important consideration, but there's more to shutter speed selection than just picking a fast enough speed to stop the motion of a moving subject. In fact, the shutter speed selection can be just as important when shooting an unmoving subject or when your goal is to accentuate the motion instead of stopping it.

Understanding Shutter Speed's Effect on Exposure

Shutter speed is one of the three basic elements of exposure. Because the goal is to balance all three elements to achieve the correct exposure for a given light level, changes that you make in shutter speed necessarily affect one or both of the other exposure elements, aperture and sensitivity (ISO).

Selecting a slower shutter speed increases exposure by allowing light to strike the ...