Thanks. This is actually an HDR vertorama of 2 rows of 3 brackets/row. The longest +2EV were 13seconds each, meaningly amazingly no-one came into frame over about 1 minute of the 6 shots of photo-taking. I was very very very lucky indeed with that, but I was through the door within a few minutes of opening time, and then straight up the stairs, knowing exactly where I wanted to go.