Open Photographic Society, Photographic Perception

<body> <p>Open Photographic Society, OPS. This page uses frames, but your browser doesn't support them. The following links are for search engines only, clicking them will only bring you back here!</p> <a href="perceptionintroduction.htm">Perception - introduction</a> <a href="perceptioncurvature.htm">Perception - curves</a> <a href="perceptioncolourspreading.htm">Perception - colour spreading</a> <a href="perceptionperspectiveillusion.htm">Perception - perspective illusion</a> <a href="perceptionheightestimation.htm">Perception - height estimation</a> <a href="perceptioneyesok.htm">Perception - eyes OK?</a> </body>