Histogram A histogram is a graphical representation of the distribution of tones and luminance levels in an image. It displays the range of brightness values from black (0) to white (255) along the horizontal axis, and the frequency or number of pixels at each brightness level along the vertical axis. Histograms provide valuable information about the tonal distribution and exposure of an image, allowing photographers to assess the overall brightness, contrast, and dynamic range of their photos.
A well-exposed image typically has a histogram that spreads across the entire tonal range without clipping at the extremes (i.e., no data loss in the shadows or highlights). Photographers use histograms to evaluate exposure accuracy, identify areas of underexposure or overexposure, and make adjustments to exposure settings accordingly. |