Part of the wonder of movie-making is just how they fool the audience's eyes. Here are a few examples from Joel and Ethan Coen's True Grit set in Granger, Texas:
Filming is taking place in the spring, but the story is set in winter, so a worker had to meticulously remove all of the new leaves from this pecan tree!
Smoke pots were used to add a spooky feel to the street.
Got a telephone pole that is not true to the film's time period? Make it into a tree.