I am a motion graphics designer, and I have been hired by a professor at Stanford University to make a series of videos to be used for instructional purposes for his students. Since the videos are being used for educational purposes, do I have to pay for rights to use copyrighted images? Currently I am just using images that are in the public domain, but sometimes its hard finding an image I want, and it would just be easier to use an image I found of google images or a similar site. I'm also not sure whether if the professor will be selling the videos or providing them for free to his students.