Shooting in a museum where flash is prohibited is tough, but modern DSLRs are actually pretty good at it.A fast fifty is the go. My EF 50mm f/1.4 is a great lens, but the depth of field is sooooo narrow.
Hardware: EOS 1D MkIIN, EF 50mm f/1.4
Exposure: ISO400, 1/50s @ f/1.4, 50mm (65mm eft.)
Post: Sharpening, white balance.