Let's say I want to create a composite image of a person standing in front of the London Bridge and I own (shot) the isolated "person" image and now need to get a photo of the bridge. No, I cannot afford to fly to London and take the photo myself.
And suppose I find the perfect London Bridge photo on Flickr (or any source) and contact the photographer so I can buy the copyright to the photo, how do I convey to contributor sites like iStock that I own the copyright to the photo -- even though I did not take it -- but only paid for it and now have a signed document stating that I am now the copyright owner provided by the original shooter.
So the short question is; how do you composite image contributors source and acquire legal rights to images that you did not take? How do you convey your copyright ownership when submitting your work?
Thanks for your replies