Beginning of film after stormtroopers raid the rebel ship. In the scene where Darth Vader picks up a Rebel in a choke grip and demands the whereabouts of the stolen plans to the Death Star.

Look at the stormtrooper positioned in the doorway behind the rebel. His feet are about a shoulder width apart.

The camera jumps in to the feet of the rebel to show he is dangling above the ground. Now you can still see the stormtrooper behind and the legs are close together with ankles touching!

When the camera moves away again, you can see that the stormtrooper once again has feet apart... further apart than the first time! (This happens about when Darth Vader asks "If this is a Counsellor ship, where is the Ambassador?" breaking the Rebel's neck before throwing him against a metal tank in a corner of the room).