Bright field illumination
With bright field illumination (see also direct incident light), the camera is positioned exactly in the direction of reflection of the light rays and detects smooth surfaces particularly clearly, because the rays are reflected back in their original direction on smooth surfaces.
An example of bright field illumination is coaxial illumination, in which the illumination and camera are directed vertically onto the test object. Alternatively, the camera and lighting can be arranged at a slight angle at the same angle (angle of incidence = angle of reflection) so that the reflected light from the lighting falls directly into the camera. In both arrangements, the light is scattered away from irregularities in such a way that they appear dark and can therefore be easily detected.
The opposite is dark field illumination.
