IDS Software Suite 4.96.1

Definition

The dynamic range (also known as contrast) of an image refers to the ratio of the largest brightness value to the smallest brightness value. In other words, a scene has a high dynamic range if it contains both very light areas and very dark areas at the same time (example: an image of a person with their back to the sun). A scene may also exhibit great brightness with minimal dynamic range because there are no dark areas (example: looking directly at the sun).

Measuring dynamic range

Dynamic ranges are usually specified in the logarithmic unit dB (decibels). The dB value expresses the factor by which the highest brightness value is greater than the lowest brightness value. The ratio of two brightness values, l1 and l2, can be converted into a value D in dB with the following equation:

A typical image sensor with a dynamic range of 60 dB could image a scene dynamic of 1,000:1, i.e. the highest brightness value is 1,000 times brighter than the lowest brightness value. The human eye can perceive a dynamic range of up to 100 dB within a scene, which corresponds to a brightness ratio of 100,000:1. The following table shows the corresponding dynamic range for different values in dB.