Admiring Michelangelo's David/Apollo

Good shot. I don't know the Washington DC museum but here in Philadelphia, it is so dark inside it prevents shooting with a medium format camera...

Some rooms at the National Gallery (particularly on the lower floor) are painfully dim, but the main floor is marginally hand-holdable with 400 speed film if you have a reasonably fast lens. Most of the time you'll be shooting somewhere around f2.8-f4, at 1/30th or maybe 1/15th. And yes, I can pull that off with the Rollei if I'm careful, because it has no mirror, and a leaf shutter that doesn't create whole-camera vibrations.