FujiFilm XQ1 Owner's Manual page 25

Histograms Histograms
Histograms show the distribution of tones in the image. Brightness is shown by the
horizontal axis, the number of pixels by the vertical axis.
Optimal exposure: Pixels are distributed in an even curve
throughout the tone range.
Overexposed: Pixels are clustered at the right side of the graph.
Underexposed: Pixels are clustered at the left side of the graph.
Before You Begin
Pixel brightness
Shadows Highlights
Parts of the Camera
11