Visible crew/equipment: Near the very beginning, when Dorothy is with Prof. Marvel, after she runs out of his trailer and the wind starts blowing, he follows her and goes towards his horse tied up outside. As he's walking towards the horse, you can see the shadow of a boom mic along his trailer.
Visible crew/equipment: When Dorothy lands in Oz and exits the house to Munchkinland, the camera pans around the land. When it slowly pans over a large bed of tall flowers, you can clearly see a very large shadow passing over them. Obviously the shadow of camera equipment or a camera crane.
Visible crew/equipment: As Dorothy is leaving Munchkinland the shadow of the camera on its dolly can be seen on the floor to the right of the screen as several Munchkins almost get run over. The shadow of the cameraman's head can be seen on the bottom right of the screen as they pass her house.
Visible crew/equipment: The four run away from the guards and leave the tower where the Wicked Witch is eventually melted. If you look closely in the two long shots from above them, the Tin Man reflects the bright stage light that is placed below them at the first bend of the walkway, on top of the Witch's castle.