On Earth, if you kick up dry sand or dirt you inevitably get a billowing cloud of dust that hangs in the air, slowly falling back to the ground. Footage taken on the Moon, however, shows an entirely different behavior: the lunar dust falls quickly to the ground, tracing a parabolic arc. This is due to the lack of an atmosphere on the Moon and is one of the best pieces of evidence proving that the Apollo footage was actually shot in an airless environment.
The following sequence is a detail from three consecutive frames of the 16-mm Apollo 11 movie footage, when the astronauts performed a series of experiments on the behavior of lunar dust and kicked it up repeatedly.
While this effect can be rather difficult to perceive in still images, it is very clear in movies and TV recordings. Here are some examples.
How would it have been possible to obtain such an effect repeatedly on a movie set, using the analog technologies of special effects available in the 1960s? It certainly wasn't feasible to place the entire set, studio lights, cameras and crew in a huge vacuum chamber. It would have been easier to just go to the Moon and shoot the footage there.