Superman IV: The Quest for Peace (1987)

Continuity mistake: In the hotel room, the swimming pool's waters are flat, then when Superman arrives at the terrace behind they are very rippled, then a frame later it cuts to Lois greeting Super and they are totally flat again.

Sacha

Continuity mistake: When the movie starts, the cosmonaut is standing up straight on the spaceship. A frame later he is laying horizontally plus he is suddenly attached to some sort of tube.

Sacha

Continuity mistake: When the movie begins, the cosmonaut has some sort of big compass attached to his legs that disappears in the wide shots.

Sacha

Revealing mistake: When Lacy floats in space, Superman saves her and heads towards Earth. When he comes back, the shot of the Earth behind is the same one from before, yet reversed.

Sacha

Other mistake: When Lois and Superman fly together, the part where they fly over some horses is the very same shot as when they fly over the Golden Gate for the second time.

Sacha

Other mistake: When Superman breaks his ice cage and makes it explode, a long black rubber band flies away. Where the heck did that come from?

Sacha

Revealing mistake: When Nuclear Man melts the rifle, note that the SWAT member is holding the barrel and he slides his hand away slowly to make the barrel bend downwards. He was obviously holding it up. If he had burned himself he would've moved faster.

Sacha

Revealing mistake: Both explosions on the sun are the same shot repeated twice.

Sacha

Factual error: Superman places the nuclear missiles in the giant disposable bag in space, throws them at the sun, and the bag burns up when it hits the sun. In reality, the bag would have burned up long before hitting the sun. (00:35:35)

Revealing mistake: Obvious doll replaces Nuclear Man when he falls into the chimney.

Sacha

Continuity mistake: Lex is a bald man, except for this movie where he has very obviously natural hair.

Sacha

Visible crew/equipment: When Superman saves the cosmonaut, stage lights are reflected on his visor.

Sacha

Revealing mistake: When Nuclear Man flies through the ceiling for the first time, the first glass he crashes into is noticeably different than the others surrounding it, revealing it's a prop.

Sacha

Other mistake: When Lenny has the prison guards locked in the car and is putting the top up, the steering wheel is spinning but the front wheels aren't moving. The amount of revolutions of the steering wheel is mechanically impossible also.

Continuity mistake: After Superman ducks the moon rock, there's a close-up of Nuclear Man's black boot stepping on Superman's boot, yet in the next angle, it's Nuclear Man who's yelling in pain. It should be Superman instead.

Sacha