Light is such a fascinating thing. Wave or photon, it creates impressions. Not just of what it reflects from, but on the overall quality and character of how we experience the world. Its impact on our emotions and our perception of space can be profound. It is the one way where we can truly freeze a specific moment in history and carry it forward into the present and the future with us. It is chimeric and emotional: many people can look at a single image and yet describe it (what they see and how it makes them feel) in a multiplicity of ways. And its reach, back through the visual history of our species, as a marker of how we move through time, is staggering.