Visible crew/equipment: When Superman and the super villain are fighting on the moon, when Superman flies in and lands at the beginning of the fight, you can see the cables that are suspending him.
Visible crew/equipment: After Superman is seen aged holding the green glass, Nuclear Man is seen ascending and wires are visible.
Visible crew/equipment: When Nuclear Man turns Luthor's assistant around on the air, supporting wires are visible.
Visible crew/equipment: In the quarry, when the cops' car flies up the air you can see the ramp used to lift it on the lower left side of the screen.
Visible crew/equipment: When Nuclear Man's laser beams send Superman flying away on the moon, the shadow of the crane moving him is visible.
Visible crew/equipment: When Nuclear Man enters the building after being told he would be taken to Lacy, he flys upward through different floors. As he's doing this you can see support wires attached.
Visible crew/equipment: Boom mic reflected on the hood of the cop car's, during the city attack.
Visible crew/equipment: When Lenny lets the guards in you can see filming equipment reflected in the rear-view mirror of Lenny's car.
Visible crew/equipment: Nuclear Man descends close to the statue of liberty to fight Superman. For a brief glimpse his supporting wires are seen.
Visible crew/equipment: When Lois is freefalling, Superman catches her and, for a brief glimpse, you see two stage lights reflected on his glasses.
Visible crew/equipment: While Nuclear Man destroys Metropolis, a bunch of people appear behind him, specially a woman with a white gabardine, a funny wig, dark glasses and a big fake nose. She reappears in a totally different place two seconds later, when the police cars arrive.
Visible crew/equipment: Lighting screens are reflected on a hotdog seller's glasses when Superman walks to the UN.
Visible crew/equipment: A moving boom mic is reflected in a car's windshield when Nuclear Man causes the explosions in Metropolis.
Visible crew/equipment: When Clark watches the subway train leave a stage light is reflected on the carriage.
Visible crew/equipment: Obvious stunt double for Christopher Reeve when lifting the lady to the China Wall; note his thick sideburns, big forehead and skinny build.
Visible crew/equipment: After Superman leaves Lenny in school, he takes off and the wooden barrier of the platform ascending him is noticeable on the lower left side of the screen.
Visible crew/equipment: When the cosmonaut is fixing some cables, a crew member's hands holding the camera are reflected on his visor.
Visible crew/equipment: When the SWAT van is lifted up there is a crane reflected on SWAT van.
Visible crew/equipment: When Superman cries "Don't do it, the people" a boom mic is reflected on the glass behind.
Visible crew/equipment: During the city attack, after Nuclear attacks a bus, a boom mic is reflected on a cab's windshield. (01:10:25)
Answer: There appears to be multiple reasons. They had creative differences, ultimately resulting in a poorly received movie. Kidder said Reeves, who co-wrote the story, had an inflated ego and clashed with Furie.
raywest ★
Moreover, Mark Pillow, who played Nuclear Man, claimed that working with Reeve was quite intense.