Coaxial Lights provide a type of diffuse illumination, generated from an internal source.  The light is then deflected downward onto the imaging plane via a 50% beamsplitter, which also allows light from the object to be collected by the camera above.  Ideal for imaging highly reflective objects or where the area of inspection is obscured by shadows from its surroundings.  The result of this illumination type is to apply a sheet of light to the object from above and collect the result of how the light is reflected, scattered or absorbed.