"A question came up today as I was walking around the Metropolitan Museum of Art in New York City. People were snapping pictures; others were buying books and posters, T-shirts and all sorts of merchandising. A friend asked me if they took a picture of a Renoir, a painting that is no longer under copyright, and started selling posters, would they be violating any copyright or other rules? For that matter, would I have a copyright on that image? This actually brings up a few legal issues. So let’s take them step by step."
Read the article here.