"Devil's Island" and just look at that horrible set of creases on the backcloth. The sea is running uphill to the left too.

I tried an experiment when painting the timber "crosses" on the three wings on the right. That's real netting by the way. Each cross was slightly smaller in dimensions as the wings went up stage, in an attempt to force the perspective. It worked well until one actor entered downstage whilst another entered upstage and my little trick made the upstage one look a giant. I am sure the audience felt something was wrong but couldn't put their finger on it!