FOR MARKUS RAETZ, the dream of art is to discover ever-new images, even within a single form. Fulfilling that dream in this exhibition, he offered an experience something like being inside a kaleidoscope. The key to the exhibition lay in a room hidden off to one side. Abstract shapes cut out of thin iron sheets hung from the ceiling; on the floor, two electric hot plates had been placed on a gray wood base. Gradually, as one moved, a myriad of portraits appeared, conjured through various systems of anamorphosis. The heat given off by the hot plates moved the wires holding up the suspended shapes,