■ What is and can Back light do?
Transmitted light illumination is the choice of illumination when it comes to measuring objects as precisely as possible. The light is directed from the back of the object towards the camera.
A transmitted light is used with opaque [non-transparent] bottom film. The products (even white tablets) appear dark in the camera image. Colour or greyscale recognition is not possible when using transmitted light alone. Transmitted light in combination with incident light also enables the detection of foreign colour or false grey values, and no statement can be made about the surface.
Transmitted light systems are supplied with three colour discs, these are red, green, blue and white. The colour disc with which the size of the contrast to the object is produced is selected.