I assume that Titian's work is now out of copyright? And I find a hi-res photo of his work with no identifying data accompanying the file. How is copyright of such an image managed?
Thanks.
I believe that's a moral question. The photo belongs to someone, even if you don't know who. That photo should technically only be copied if you have permission, but it's not always possible. If you take a photo of the original Titian, you own the rights to your photo but not to the original work. If you make a photo of a work in a museum, the museum may reserve rights to photos, but they can neither own the copyright to the Titian, as well.
The problem comes if/when you made a copy of the photo of the Titian and did something with it and the original photographer somehow found out. Then, I believe you would be violating his copyright of his photo of the no longer copyrighted painting.
Based on my experience, that's what I think is correct.
If you just take a photo of a work in a museum it would be a good idea to check the museum's policies. They may not have any. In that case the digital file is yours but it can never be considered an original creation.
Edit: If, however, you make a photo of the original Titian and alter it significantly enough to create a different contextually, in essence so that the new work is "transformative", then it becomes an appropriation and then as a new artwork, can be copyrighted if there is a significant enough distinction. Again, based on my experience, but these things are mostly decided in courts if gets to that degree of seriousness.