
Cardinal Rays and Planes of a Lens
Late in January we began by considering the limitations of lens systems - namely aberrations, but only in a very general way. However, before we start detailed discussions, let me first make it clear that to every optical person in the world, light ALWAYS travels from left to right. It’s just one of those conventions that is universally accepted (and assumed in any optical discussion). In order to continue our discussion of lenses we need to define several key elements that