However, I think the laws for this vary quite a bit across countries, and in many countries the photograph is considered a new copyright work. In general it's pretty frustrating how many legal barriers there are to accessing and reusing old works of art. Thankfully a growing number of museums have made things easy with clear copyright releases (Rijksmuseum, Paris Musées, the MET), but others seem more interested in preserving their ability to sell prints.
However, I think the laws for this vary quite a bit across countries, and in many countries the photograph is considered a new copyright work. In general it's pretty frustrating how many legal barriers there are to accessing and reusing old works of art. Thankfully a growing number of museums have made things easy with clear copyright releases (Rijksmuseum, Paris Musées, the MET), but others seem more interested in preserving their ability to sell prints.