How does underexposure typically affect digital images?

Underexposure in digital images typically results in the introduction of noise, which becomes particularly noticeable in the darker areas of the image. When an image is underexposed, the sensor does not capture enough light to accurately represent the scene. As a consequence, during the post-processing phase or when attempting to brighten the image, the lack of adequate information in the darker regions leads to this unwanted noise. This noise may manifest as graininess or random variations in brightness and color, which can degrade the overall quality of the image.

In contrast to the other options, underexposure does not increase clarity; rather, it often causes loss of detail, especially in shadow areas. It also does not inherently create excessive contrast. Although underexposure might make certain areas appear darker, contrast refers more to the difference between light and dark regions rather than the amount of light captured. Decreasing exposure time is related to reducing the amount of light hitting the sensor, which actually contributes to underexposure rather than being a direct effect of it. Thus, it’s clear that the introduction of noise is a primary characteristic of how underexposure affects digital images.