In the spirit of using seats as flotation devices, Steven Pippin turned washing machines into cameras for his ingenious photography series Laundromat/Locomotion. How did he do it? By clamping collapsible film holders onto the drums of 12 front-loading washing machines and fitting the glass doors with shutter/lens devices that block out light. He then loaded sheets of film into the holders, attached flashbulbs to the tops of the machines, and connected the flash and shutters to trip wires, which he laid across the floor of the New Jersey laundromat where he took the pictures. When he strode across the laundromat (wearing a dark suit, naked, even on horseback), he tripped the wires and activated the cameras, which took grainy, antique-looking shots of him in motion. These dovetailed nicely with Pippin's ambition, to pay tribute to experimental San Francisco photographer Eadweard Muybridge, who used multiple cameras tripped by strings and rubber bands to take pictures of racehorses and men performing simple tasks back in the 1870s. "Steven Pippin: New Work" opens along with the archival group photography shows "The Photographic Era: Highlights From the Permanent Collection" and "Photography After Modernism: Extensions Into Contemporary Art" at 11 a.m. Friday at the SFMOMA, 151 Third St. (at Mission), S.F. Admission is free-$8; call 357-4000.