You can't make a photograph without light, at least not in the visible range, and you may have noticed that I'm often attracted to sources of light when I choose a subject to photograph. (Apparently it's called positive phototaxis.) This evening I was passing a new office development next to Cannon Street station in London and was drawn towards its foyer, which will almost certainly become a top nightspot for moths when the warm weather begins. How the security guard is sleeping through this amount of illumination I just can't imagine. And I promise you I didn't adjust the colours.