Certified Professional Photographer (CPP) Practice Exam

A histogram is a graphical representation that illustrates the distribution of tonal values in an image. It shows how many pixels are present at each level of brightness, ranging from black (0% brightness) to white (100% brightness), thus providing a clear overview of exposure levels. When evaluating a histogram, a photographer can assess whether the image is underexposed (lots of data on the left) or overexposed (lots of data on the right) and make necessary adjustments to achieve a well-balanced exposure.

While the other choices relate to aspects of image quality, they do not encapsulate the primary function of a histogram as effectively as exposure levels do. For example, color balance pertains to the distribution of colors in an image, which can be assessed through other tools; texture details focus more on the surface characteristics and details within the image rather than the overall tonal distribution; and brightness levels are somewhat related but are a broader term that does not specifically cover how the information is graphically represented in terms of exposure distribution within a photograph.