On the Brightness in Images Captured with Conventional and Compound Eye Cameras

In this paper we consider cameras as belonging to one of two types: single aperture (conventional) cameras, and multiple aperture (compound eye) cameras. The eyes of insects are well known examples of the second type. Recently Fraunhofer Institute announced the manufacturing of a compound eye camera, which is very thin and has potential applications unthinkable for the traditional single lens camera. In the case of compound eye cameras we describe a fundamental dependence of image brightness on the distance to the object. This is a property not observable in single lens cameras. We derive the mathematical expression for the brightness in images as a function of the distance to the object. Further, we provide an analysis of the behavior of the two types of cameras in this respect. Our conclusion is that compound cameras are fundamentally the appropriate devices for capturing light field information because of their correct sampling of radiance.