G'day Pedro,
while we're a topic, a couple of months ago I took pictures (on a museum) of ancient mayan sculptures. Unfortunately I was on a hurry so I couldn't go talk with staff. Now, who owns the copyright? Those sculptures are like a thousand year old, but pd-old doesn't apply (it will apply 100 years after I die in case I actually hold the copyright of my pictures)
Can I upload such pictures to wikipedia? Can museum claim copyright on the ancient sculptures? and if so, can it claim copyright on my pictures?
I think a photo of a 3D sculpture has a lot more "creativity" in it than a scan of a painting: choosing the angle, and so on. Such a photo could well be copyright you. If I'm wrong, then the copyright would be held by the original artist (in other words, PD-old).
Either way, the museum has no claim on you. I believe that's why some museums don't like you taking photos.