The luminance of objects. The brightness of any area of the subject is dependent on how much light falls on it and how reflective it is. Brightness range is the relationship we perceive between the light and dark subjects in a scene. Brightness contrast is a judgment of the relative measure of that range, such as high, low, or normal. Brightness values are sometimes referred to as EV (exposure values), a combination of aperture and shutter speed. Brightness values in the scene are translated to tonal values on film.