The idea is this. A number of you meet up in the vicinity of some interesting scene. You synchronize your watches, get out your cameras, and disperse like secret agents into the crowd to take photos. Some will take four or five beautiful, professional images of luminous beauty. Others (me) snap up a mish-mash of scraggily composed, poorly-focussed rubbish and hope to sort out a few accidental gems afterwards. An hour or so later, you re-meet to see what you got.
Yesterday, the assignment was the Chocolate Festival behind the Royal Festival Hall.
I've never done anything like this before. I couldn't even stay for the "show and tell" part yesterday, as I had a book group to go to (they were talking about my book - a first for me!). But even during that half-hour dip into the world of photographic explorers, I was amazed at how liberating it was.
Yesterday, instead, I relaxed. This mission was nothing to do with me: it was just a job I'd been given. My alibi was perfect. I had my sense of entitlement. It was as if I was wearing an "Authorised Photographer" badge that only I could see - so I got on with the job.
Also, I knew I wasn't alone. Every now and then, as I roamed (we were all separately circling the clump of chocolate stalls, like sharks circling a raft of shipwreck survivors), I'd pass another agent. We'd give a sign: a smile, a lift of the eyebrows, a waggle of cameras. Sometimes we'd speak: "Having fun?" - "Getting any good ones?"
And no one noticed. They just kept eating their chocolate...