Large visible differences in brightness are characterized by:

Large visible differences in brightness are characterized by short gray-scale, high contrast, and few shades of gray. This means that when there is a significant contrast between light and dark areas in an image, we typically have a limited range of gray shades represented. High contrast allows distinct separation between different brightness levels, leading to a striking visual effect where dark areas are very dark and light areas are very light.

In this context, a short gray-scale means that the transition of gray tones is limited, which reinforces the perception of high contrast. The minimal number of shades of gray helps in creating a clear demarcation between different brightness levels, making the differences more pronounced and easier to perceive. In imaging, this is particularly important for accurately assessing features and qualities within the image.

Conversely, the other options would describe alternatives that do not align with the characteristic of large visible differences in brightness, such as longer gray-scales, which would imply a more gradual transition between shades, leading to lower contrast and a more nuanced representation of luminance rather than stark visual differences.