Latab Dark field lighting is the optimal lighting form for the emphasis of edges. Because of the parallel direction of the light in relation of the recorded object, the light is only reflected at the edges of the object toward the camera. For different object sizes, there is a wide range of ring diameters from 58 up to 281 mm available. To define the site of the dark field ring light , there must be sufficient distance between the object and the interior border of the ring light (at least 20 to 40 mm) is available. The working distance depends upon the size of the dark field ring light and is 20 mm maximum.