This series arises from the intrinsically slow nature of the calotype process I am using to create the images.. Exposures are anywhere from 6 minutes to an hour. Any movement is averaged out and human activity is only registered as what the early practitioners termed “Human Mist”. I have been working on this series since 2012 but the meaning of the work has morphed in that time. I see it now as a study in the ephemeral nature of human existence. Having almost died in November 2015 when I was struck by lightning in a remote corner of Mozambique, this series has taken on a fresh relevance for me in considering the precariousness of my own existence. In one image, Sé de Lisbon, I appear as a ghost myself – a sort of 19th-Century selfie.