That would probably be a policy set by the publisher. National Geographic Books likes to source that 
sort of imagery. Others may not.  If the supplier insists on credit for an image they do not own a 
copyright on, it is your call, since it is not a straight presentation of the image, it is 
incorporated into a new creation.


Cindy Shaw wrote:
> Thanks, Britt and Frank - this is pretty much what my understanding was, but good to have it confirmed.
> On the same lines - what about satellite imagery used to drape over terrain models? Does that need to be credited?
> Cindy