Lighting angles in industrial image processing - The influence of incident light and transmitted light on camera vision

When selecting the type of lighting and its arrangement, there is a fundamental difference between

• reflected-light lighting, which comes from the direction of the camera and is thus positioned above the object plane; and
• backlight lighting, which is positioned behind the test object.

When choosing a lighting arrangement for reflected light, the ground rule is the Law of Reflection – which you probably still remember from school. This in itself is naturally common knowledge. Yet the awareness – and more importantly, application
– of this simple law when selecting an appropriate lighting type and arrangement is really and truly half the battle.