Best movie mistake pictures of 1953
Visible crew/equipment: Opening credits (also a few minutes in) has a fiery spaceship crashing into the camera for this was a 3D movie. What's interesting is that a mirror can be seen on the left portion of the screen just before the collision. This was apparent at the theatres and on the VHS tape release. For some reason, the DVD release has it cropped out and now the spaceship is off-centered at the beginning (fortunately the bonus material still shows it).
Continuity mistake: After the mermaids splash Wendy with a ton of water, her hair is wet and you can tell because it is sort of hanging down and drooping. Then they cut away, then when they cut back to Wendy, her hair is perfectly dry.
Visible crew/equipment: When the martian space ships first appear you can see the wire suspending the models. You can clearly see the wires every time you see a martian or martian space ship.