If I take a photo at lets say a dog show or a dog training session, I take photos of other peoples dogs, I have copyright over the photo as I took it. BUT - Do I have any authority to use these images without the dog owners permission? Do I need like a model release form in order for me to use these photos (even as part of my portfolio). Am I allowed to sell these photos without permission of the owner? Can I sell the photos to the dogs owner? How does it all work???