I'm an art historian trying to amass my own photo archive of Greek and Roman art, so mostly large pieces of sculpture and small three-dimensional artifacts (vases, bronze implements, etc.). The objects I photograph are mostly inside museums, where the lighting is poor and tripods are forbidden. There are exceptions, of course; some museums allow tripods on low-traffic days, and some will allow the use of one by prior arrangement, but for the most part, I'm stuck with low light and a handheld camera. I'm starting to invest in better equipment to deal with the challenges of museum photography, but can't afford a whole suite of lenses. I figure a fast prime lens is probably the way to go, but I'm not sure how wide it should be. One of my friends said he bought a 50mm f/1.4, but he is disappointed in its very shallow depth of field. He described being unable to get both the nose and the ear of a sculpted portrait in focus at once (when shooting details), or else being unable to step back far enough to get a whole statue in the frame. (I know he's no photography expert, so it's possible he's just doing something wrong.) In my perfect world, I would be able to photograph statues in low light and have the shots turn out nice and sharp and with a blurred background to help the statue stand out. So: would a 20mm f/1.8 be fast and wide enough? Or would it be too wide? Would I lose the blurry background when getting a whole statue in the photo? Would a 24, 28, or 50 be better?