In photography, which statement defines exposure?

• A. The angle of light entering the scene.
• B. The amount of time light has to enter a camera.
• C. The color temperature of the light.
• D. The distance between light source and subject.

Answer: (B)

Exposure is about how much light reaches the sensor to determine how bright the image will be. The option describing the time light has to enter the camera matches the shutter speed, which is the primary control for how long the sensor is exposed to light. If you open the shutter longer, more light hits the sensor and the image brightens; if you close it quickly, less light hits and the image darkens.

The other aspects listed don’t define exposure: the angle of light affects direction and quality of lighting, color temperature relates to white balance, and distance to the light can change brightness but isn’t the definition of exposure itself. In practice, exposure is controlled by shutter speed (time), aperture, and ISO, with the shutter speed being the explicit time-based factor described here.