The other day, I was in line at the drugstore, and I am sure that everyone can relate to the scenario of getting stuck behind the scratch-and-win-ticket-picker. To add to the frustration, the lady behind me kept sidling up as close as she could to me, violating that invisible barrier known as personal space. 

Having spent quite a lot of time in France and Europe, I've observed that the concept and size of ''personal space'' varies substantially from culture to culture, and the North American and European versions are radically different. We North Americans skew towards a generously wide circle. And most people respect that. Get on a train in Europe, and you learn very quickly that having a couple of square centimetres in which to breathe is considered ample.

I think my own definition of personal space is even wider than most - physically, emotionally, professionally I prefer to hold people at a comfortable arm's length. And any incursion therein immediately raises my hackles.

In art and photography, there's a notion of ''negative space''. It's the part of the composition that is empty or void, that is to say the space surrounding the subject or subjects. It could be sky or a background or blank canvas. It defines contours and gives context. And it allows the composition to breathe. In my mind, it's every bit as essential and important a player as the active components in the frame, all the while doing its best to efface itself and conceal its very existence. Completely negative, and at the same time anything but.