Read the linked paper, it's actually very good. It looks like they used good science in testing this: "From our study, we conclude that both our method and the

Read the linked paper, it's actually very good. It looks like they used good science in testing this: "From our study, we conclude that both our method and the light probe method are highly realistic, but that users can tell a real image apart from a synthetic image with probability higher than chance. However, even though users had no time restrictions, they still could not differentiate real images from both our method and the light probe method reliably."