Corrected entry: During Westley and Inigo's fight atop The Cliffs of Insanity, the sky behind them is obviously a matte painting because the clouds never move.
Corrected entry: When the masked man is climbing the rope just before Vizzini cuts it, it's clear that he is being pulled up by another rope or wire. He flies up the rope and is moving up faster and farther than his arms are moving.
Correction: This is deliberate to emphasise his almost superhuman abilities - this is a fairytale after all.
Corrected entry: The Machine is powered by a water wheel that takes a while to get going (not to mention how long that flood gate took to open and whatever moves the water down the slough). However, when the Count switches it off, and an instant later the camera cuts to a wide shot - the Machine has stopped completely. It should have slowed gradually to a halt because of inertia.
Correction: It could have a built-in braking mechanism that kicks in when the gate is closed.
Corrected entry: When Westley and Buttercup come out of the quicksand (an aggregate of water and sand, basically mud), they're covered with sand. Within a few seconds, they are clean - the wet sand should be quite sticky.
Corrected entry: When Inigo, Fezzik, and Westley are on the castle wall, Westley says, "There may be problems once we get inside" and Inigo is heard to say "I'll say" but his lips don't move.
Correction: A person's lips don't move all that much when saying "I'll say". I zoomed in, and he is saying it. You have to look pretty close, though.
Corrected entry: In the scene where Fezzik is hurling a rock at Wesley, watch carefully and you'll see the rock explode before it hits anything.
Correction: Untrue. It hits the boulder directly beyond him. It's just somewhat tough to make out the depth of field because it's viewed almost straight on. Once the debris has cleared you can see the mark the smaller rock made on the boulder.
Corrected entry: When the boat reaches the Cliffs of Insanity, there's a long shot of Buttercup, Vizzini, Fezzik, and Inigo stepping away from the boat. But who's the fifth guy?
Correction: There's no fifth guy. I thought this was right at first, but in frame-by-frame on DVD what you see is that Fezzik gets off first and steadies the boat, then Buttercup, then Vizzini, then Inigo who is holding something man-sized out at arm's length, which appears like another person. It's actually the harness they then strap Fezzik into, for the rest of them to ride.
Corrected entry: In some of the shots where Westley and Inigo begin to duel, one can see what appears to be a leftover 'practice' sword with a black glove on it sticking into the ground. It first appears in front of Inigo's stomach as they begin to hit swords.
Correction: That is not a practice sword, it is Westley's scabbard.
Corrected entry: Westley states that no one has ever survived the Fire Swamp. If that is so, then how does he know what the 3 dangers are? Where did he find out if no one has ever survived to tell the tale?
Correction: It's likely that the legend has been documented somewhere, as is common in films like these. He could have read about the 3 dangers in a book written by a sorceror or other mystical being, or he could have heard it orally from a wise man or an elf.
Corrected entry: In the beginning of the movie when Westley is chasing after Buttercup, everyone climbs up the cliff. But later the prince and his men are on horses, tracking the footsteps of the other. Horses can't climb cliffs.
Correction: Nor did these horses have to. Humperdinck and his men approached from a different route. They only started at the top of the Cliffs because Humperdinck, having orchestrated the kidnapping, knew exactly where to go.
Corrected entry: In the shot of Westley climbing the Cliffs of Insanity, they show where the boats should have been moored but neither of the ships are there.
Corrected entry: As the story reaches the bottom of the Cliffs of Insanity, we see Vizzini et al exit their boat. However, when the Man In Black's boat reaches the landing area as well, the first boat is nowhere to be seen.
Correction: There's a shot where you see the boat drift away because it wasn't moored properly
Correction: Clouds don't visibly move if there's no wind to move them.
tw_stuart