Walter Wick's Optical Tricks

Wick (photographer of the I Spy books) reaches into his bag of photography tricks and pulls out surprises galore: his baker's dozen of fascinating illusions will stump readers of every age. Nothing is quite what it seems--images that appear indented in clay suddenly pop out in relief when the page is turned upside-down; a handful of fish multiplies into an endless school through the clever use of mirrors; the middle of three columns in a structure seems to disappear somewhere between base and ceiling. Crisply photographed and composed in largely primary colors, the images pack a nifty one-two punch. Best yet, Wick generously reveals the tricks of his trade at the end, explaining the difference between true and false perceptions and showing how, for example, he created the illusion titled ""In Suspense"" by placing halves of objects on a mirror to make them appear as wholes, floating in space. Part M.C. Escher, part ""Magic Eye,"" but wholly original in their presentation, these irresistible puzzles are nothing short of visual catnip. Ages 7-up. (Sept.)