Photon counting is a very valuable technique; it is much more widely used than the current discussion suggests. This article is focused solely on microdose X ray techniques. The photon counting technique probably deserves a separate article that could be referenced here and from other articles such as the photomultiplier. As the discussion here says, direct photon counting achieves much lower noise levels when the photon flux is low. For instance, photon counting with photomultipliers is used in high-sensitivity fluorometers. As a source, you can find a good discussion of the technique in the Hamamatsu Photonics pmt handbook --AJim (talk) 21:33, 12 June 2012 (UTC)
