Revealing mistake: When the villains enter the oval office, the whole White House behind is a cheap set with painted columns, furniture, fixtures and switches (even the bullet holes are painted!). (01:16:29)
Revealing mistake: When Superman flies towards the White House, in the close-up his cape and flag flutter at a normal speed, but in the wide shot they move really fast, quite comically actually, revealing that the scene has been speeded-up.
Other mistake: When Clark and Lois return from the Fortress of Solitude in a green car, the footage is the exact same one used in Superman I when Luthor later crashed that very same car (time code for Superman I 1:34:04 vs 1:18:25 for Superman II).
Continuity mistake: While in the water, Lois grabs the log with her right hand. A shot later she is away from the log and she grabs it again, though now she uses her left hand.
Revealing mistake: When Lois jumps in the river, she is replaced by a very obvious mannequin that floats stiff. Furthermore, the current tilts the dummy and its two arms bent like a sex doll's are perfectly visible.
Continuity mistake: After Zod launches Boog through the truck the cop asks if he's OK and he and the kid turn sideways an look at him. A shot later they are facing straight.
Continuity mistake: When Zod launches Boog through the cafe window, he lands a couple meters away from the cop, but a shot later he's at his feet.
Revealing mistake: When Superman arrives at the tropical place, the sea doesn't move, revealing it's a very obvious still picture where a flying Superman has been inserted.
Revealing mistake: After the army jeep drives through a House in East Houston, notice the driver's stiffness despite the crash and fall, revealing it's a dummy.
Revealing mistake: When the 3 villains start blowing at the people in Metropolis, the papers come blowing from the left and right sides of the set, revealing where the huge fans where placed to achieve the effect.
Revealing mistake: When Ursa throws the sewer lid at Superman a sticky object protrudes from his back, revealing the mechanism that pulled him backwards.
Audio problem: During the disappearing/reappearing scene, Superman grabs Zod's neck and cries "Wrong again, Zod!" but his mouth isn't moving.
Visible crew/equipment: When the villains enter the fortress, the moving shadow of the crane used to make them fly is visible when the last villain flies towards the upper left quadrant.
Continuity mistake: When the movie begins Zod breaks the red glass and there's a brief shot of Ursa looking in fear. Her hair is longer than in the previous shot.
Revealing mistake: Right when the Metropolis fight is about to start, Superman flies to the Daily Planet and passes by a building. Check the pattern on the windows and you'll notice that the same small door on the left appears almost everywhere, revealing that a miniature was used.
Continuity mistake: When the villains are trapped in the phantom zone (filmed by Richard Donner) Zod, Non and Ursa (from left to right) are tightly pressed against a glass. When the elevator explodes and are about to be released (filmed by Richard Lester) not only are they not pressed, but neither in line, having changed positions (and looks, as already listed): Non now stands above Zod and Ursa.
Continuity mistake: In Krypton when Non breaks the guard's neck the guard presses an emergency button. In the wide angle all of his fingers are extended, but in the close-up only the index is. This changes back and forth.
Revealing mistake: The villains send cars flying through the air. This was achieved with detailed scale model cars in a scale model Metropolis. But in order to mimic the blown-away citizens they use cheap mannequins that move on some sort of conveyor belt. (01:43:50)
Revealing mistake: When the villains blow away the stuff in Metropolis, the fire hydrant falls down and reveals it wasn't fixed to the ground, a blatant prop.
Audio problem: When Ursa lifts the bus she mumbles and laughs, but her mouth is closed.
Answer: Superman was well educated regarding his home planet's history. All this information was left for him by his parents at the secret installation at the North Pole.
raywest ★