In the scene near the beginning of the film, when the 2 brothers are fixing to leave to join the army. After the mother gives them the flag, the shot changes to the 2 brothers. You can see the boom mic and the camera in the reflection of their shiny brass buckles.
General Robert E. Lee was shown throughout the movie as wearing the three star insignia of a Colonel, rather than the three stars surrounded by a wreath as was the proper insignia for all Confederate generals. General Lee actually wore this throughout most if not all of the war, and this is accurate.