Epstein (1965) presented observers that photographs of a quarter, dime, and half-dollar were all equal in physical size. The photographs were at the same distance from the observers. Using only one eye the observer said that the dime was closest, the quarter was farther than the dime, and the half dollar was farthest of them all. Using two eyes this was not the result, because they were aware of the distance. So, this Epstein's results showed that familiar size is most effective when other information about depth is absent.