Twilight view of the Chicago River Walk district with illuminated skyscrapers reflecting in the water.

From the fifteenth floor of the Renaissance Hotel, the Chicago River bends through its architectural corridor in a thirty-second exposure that turns the predawn waterway into a ribbon of light — Marina City's twin corncob towers to the right, Trump Tower and the Wrigley Building beyond, Mies van der Rohe's IBM Building as a cool dark rectangle amid the warmth. Greg titled this image "Sicut Ante Lucem" — as before light — a name that describes the exact quality of a sky that has not yet decided between night and dawn. This panorama required a fifteen-floor vantage point that few photographers can access, and the thirty-second exposure demanded a sky that would hold still long enough to resolve. Chicago at this hour feels earned.