Star Trek IV: The Voyage Home (1986)

Visible crew/equipment: During a close up of the police officer's sunglasses, when Chekhov is asking for directions to Alameda, some crew are visible in the left lens. They are a line of people trying to stay out of the camera. (00:43:30)

Continuity mistake: In the scene where Spock gets confronted after swimming with the whales: you can easily see before he puts on a robe, that his clothes are completely dry, yet he had just been swimming in the shot a moment earlier.

Visible crew/equipment: At approximately 01:32:50 on the Blu-Ray, you can see a diver releasing the mechanical whales. He is on the far right side of the screen, you can make out his head, body and left hand. He is visible for a good 8-9 seconds. If you have a different media source, it's during the Bird of Prey decent. You see a closeup of Kirk, followed by a closeup of Uhura and Gillian, then a close up looking down on the harpoon. It's in the following scene. (01:32:50)

Continuity mistake: In the scene with Kirk and Spock walking the marina green under the Golden Gate Bridge, the leading shot shows blue sky. As the camera changes angles, the background changes to completely fogged in. Not shot on the same day.

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Factual error: At two points in the film, the Klingon vessel Bounty traverses the distance from the Earth to the Sun at maximum speed, in excess of Warp 9. The latter sequence requires about 111 seconds from the time Sulu says "Aye sir, warp speed" until they reach the Sun. While there is no real science behind Star Trek's "warp technology, " the Starfleet Technical Manual provides a formula for calculating warp speed, whereby Warp 9 translates to about 136 MILLION MILES PER SECOND. The Earth is only 93 million miles from the Sun. In the apparent time that it takes the Bounty to reach the Sun, a starship traveling at such ferocious velocity would already be outside of our known solar system and deep into interstellar space.

Continuity mistake: The crew wrote 'HMS Bounty' in large red letters on the side of the Klingon Bird of Prey, but in all subsequent flying shots, the large red writing is never seen again. It's not burned off as you only get heat entering the atmosphere if the speed is sufficient, and it's not wind resistance either, because the lettering is missing just after they take off.

Audio problem: When Gilliam slams on the brakes, the tires make a screeching sound, but the wheels come rolling to a stop, ergo do not skid. (00:56:50)

Plot hole: If the Bird-of-Prey went to warp speed right after the whales were beamed up the ship would have already been so far away from Earth it would have been on its way back towards the sun, yet minutes later the ship is shown leaving the Earth, still at warp speed.

Continuity mistake: When we first see the whale pen it is divided from the sea by a concert wall with double gate in the middle, but when the whales are released most of the wall and gates are missing.

Revealing mistake: When Kirk and crew flee the hospital McCoy bumps a man with his leg in a plaster cast. Look closely at the cast - it is fitted over his PJ's leg like a boot, plaster casts are never fitted over clothing.

Factual error: As they descend into the park, Uhura gives a bearing and range of 283 degrees, 15.2 kilometers to the whales, which are supposedly in a marine park in Sausalito. 283 degrees would put you in the Pacific Ocean, because Sausalito bears around 360 degrees from the park. Uhura gives a true bearing to the whales, since a relative bearing would be useless once the crew leaves the park.