[en] Many investigators have substantially reduced doses in pediatric radiography by employing specialized beam-modifying filters. Image quality is not affected. The results are achieved by reducing the amount of low-energy, poorly penetrating x-rays as well as cutting back on the low-contrast high-energy portion of the bremsstrahlung spectrum. The maximum dose reduction can theoretically be achieved by employing an optimal single photon energy. The authors used the theory of information content and patient exposure to determine this energy. Its dependence on patient size and other factors is demonstrated. Experimental results using this approach are presented