Over the course of the last two decades, the Dutch photographer worked methodically on his monumental Photo Notes project: First he would select a busy pedestrian area - his favourite spots were often near shopping centres - where he would stay for 30 minutes up to a few hours. He then spent time observing passers-by before recognizing a common type, normally based on a garment, sometimes a behaviour: people in band T-shirts, fur caps or beige trench coats; young couples walking arm-in-arm; women in suit dresses; men with gelled hair or pushing shopping trolleys... He snapped them with a camera hung around his neck, attached to a trigger in his pocket. Back in the studio, the images were laid into grids called Photo Notes. Their simplicity of form and presentation belies their complex anthropological, social and artistic commentary.