This is baseball as the umpire sees it—the bulky back of a catcher's mitt, a taut grip on the bat, the sudden burst of a humming fast ball. The umpire here, toiling under a hot spring-training sun, was SPORTS ILLUSTRATED'S John Zimmerman, who carried his camera right into battle. Draping a mask (shadowy lines) over the camera, Zimmerman crouched behind White Sox Catcher Sherman Lollar as Billy Pierce, backed up by Shortstop Luis Aparicio (left) and Second Baseman Nelson Fox (right), fired a fast ball in to Earl Battey. Battey didn't hit this pitch—it was a shade inside—and the ball smacked into Lollar's big mitt an instant after Zimmerman snapped the shutter. ("Nothing happened," admits Zimmerman, "but I sure flinched.") The result: for one photographer, wobbly knees; for the reader, a fresh, firsthand look at classic baseball action.