In the conventional approach to lens imaging, rays are used to map object points to image points.
However, many students want to think of the image as a whole. To answer this need, Kepler’s ray
drawing is reinterpreted in terms of shifted camera obscura images. These images are uncovered by
covering the lens with pinholes. Thus, lens imaging is seen as a superposition of sharp images from
different viewpoints, so-called elemental images. This superposition is simulated with projectors,
and with transparencies. Lens ray diagrams are constructed based on elemental images; the
conventional construction method is included as a special case.