Visible crew/equipment: In the soda shop scene where Sandy and Danny are at the jukebox, the reflection of the boom mic is clearly visible in the chrome part of the jukebox. [True of videos and early DVD releases - in later DVD releases the reflection has been removed].
Visible crew/equipment: As the Tin Man gets to the end of his song, he's dancing in front of three mirrors. If you look past him as he's centered in the middle mirror, you can see the camera lens looking out of the canvas at him.