 Their rationale was based on the linearity of CCD and CMOS sensors, whereby the electric charge accumulated by each subpixel is proportional to the amount of light it is exposed to (plus electronic noise).Although a camera may have a dynamic range of 5 or more stops, when image data is recorded digitally the highest (brightest) stop uses fully half of the discrete tonal values.This is because a difference of 1 stop represents a doubling or halving of exposure.