Quote Originally Posted by Steve Smith View Post
What about an oil painting? Is a photograph of it a copy which can be an infringement or does it have to be another oil painting in order to infringe the original's copyright?
A photograph of an oil painting is a derivative work because both are two-dimensional imagery. Even a sculpture that copies a photograph is derivative, as was established by the Rogers v. Koons case in the Supreme Court for the US, but undoubtedly very influential on IP legal thought around the world.

However, if someone wrote an piece of music about a photograph, as Philip Glass did about Edward Muybridge (though time had elapsed on the copyright), there would not be a derivative work and no copyright problem. Likewise for a ballet about a bridge.