What does shutter speed measure?

Shutter speed is a critical component of photography that measures the length of time the camera shutter remains open when taking a photograph. This duration directly impacts the amount of light that reaches the camera sensor or film. A longer shutter speed allows more light in, which is beneficial in low-light conditions but can also lead to motion blur if there are moving subjects. Conversely, a faster shutter speed results in less light and is ideal for freezing motion, capturing sharp images of fast-paced action.

The other options address different aspects of photography. Light entering the lens pertains to exposure but is measured by aperture rather than shutter speed. The angle of view is determined by the focal length of the lens and its construction, not by shutter speed. Lastly, image quality can be influenced by several factors, including lens quality, camera settings, and environmental conditions, but it is not directly measured by shutter speed itself. Understanding shutter speed is essential for mastering exposure and achieving desired artistic effects in photography.