The symposium started with Robert de Ruyter van Steveninck talking about the fly visual system. He gave an overview of the classical optomotor studies from the 60s and 70s which dealt with ideal visual stimuli. He then went on to talk about the modern theories dealing with the different complicating factors in real world natural signals: shot noise, back- and foreground motion, etc. A very mathematical talk which showed how the modern optomotor research has now advanced light-years from the original work.