There is nothing quite like black-and-white photography and film. That luminous lime white. That obliterating black. That infinite spectrum of velvet grays—pearlescent, ashen. When color came to the photographic process, the world, like Narcissus at his pool, couldn’t get enough of its living-color reflection. Gone was a certain depth and poetry, gravity and ghostliness. With work from 204 photographers from 36 countries, this exhibition pays extravagant homage to monochrome photography, paying special attention to silver-based methods. —L.J.