The Public Catalogue Foundation has something to say about copyright. Sadly they are wrong. They say:
Is there copyright in the photographic image as well as copyright in the actual painting?
Yes, there is. The photographer uses training and skill to photograph a painting and he or she holds copyright in that photographic image. However, as part of its agreement with collections, the PCF agrees that its photographers will hand over copyright in all their photographic images for collections’ own use.
There is a word for this point of view: copyfraud. When this point of view is typically British, it is just that.
The PCF may claim copyright on the tags added to the paintings. There is no mention about this.