RIGHT PLACE, RIGHT TIME. Any sports photographer will tell you that's half the battle. Carl Iwasaki's picture of Joe Montana's game-winning throw didn't even merit inclusion in the game story. (It ran only when Montana retired in 1995.) Meanwhile, Walter Iooss Jr. had set up in the end zone and snapped a soaring Dwight Clark in what has become one of the magazine's enduring images (as the abundant yellow stickers on the slide attest). Iooss's picture, though, was the result of more than positioning. He'd been shooting the beginning of this play with a telephoto lens, but as he saw the action coming his way, he quickly switched to a camera around his neck with a 50-millimeter lens, better suited to close-up action. He framed the moment perfectly. Clark and Montana weren't the only ones to come through in the clutch that day.