"Fifty percent! It can be worse than that. I quote: "Chapin Cutler, a cofounder of the high-end specialty projection company Boston Light & Sound, estimates that a film projected through a Sony with the 3D lens in place and other adjustments not made can be as much as 85 percent darker than a properly projected film." Your best bet is apparently to (1) find a theater that doesn't use digital at all, (2) doesn't use Sony projectors, or (3) still projects light through celluloid the traditional way."