YOSEMITE NATIONAL PARK, Calif. — The photographers were packed so tightly along the riverbank that they looked like paparazzi stalking a starlet. In this case the Lindsay Lohan in question was a wispy little ribbon of water falling thousands of feet down the face of El Capitan, the world’s largest single chunk of granite.

For about one week each February, the setting sun hits the water of Horsetail Fall at such an angle that it glows, looking like a stream of lava against the darkened rock.

The so-called firefall attracts hundreds of professional and amateur photographers from across the globe, who flock to Yosemite Valley to capture the ephemeral scene.

“Firefall is like a photography tailgating party,” said Terry McCafferty, 64, a retired police officer from Fremont, Calif., who travels to photogenic places in a large white Suburban with his camera-wielding buddies.