Other: In the scene where Renfield enters Dracula's castle, it is past midnight and on the outside, it is dark. But there is a LOT of bright light streaming through the windows into the castle, throwing well-defined shadows.

Revealing: In several of the sanatorium scenes, you can see large pieces of cardboard attached to the lamps to affect the lighting.

Visible crew/equipment: Right after Dracula says "My blood now flows through her veins", he then walks across the room. As he does this, watch the lower right corner of the frame and you'll see revealed for a moment a big glaring light "hidden" on the floor behind the couch.

Revealing: When Renfield walks up to the front door of the castle, he is in a court yard where the only light comes from torches. But the light is enough to make him throw a clear shadow on the wall, and the shadow never flickers as it would in torch light.

Factual error: Dracula refers to the town of Whitby as "so close to London" when in fact it is 243 miles away.

Audio problem: In the uncensored version (certain scenes were thought too graphic, and thus a lot of copies of the movie are edited), Dracula picks Renfield up and strangles him, and Renfield is screaming. Okay, how can someone scream if they're being strangled? (The censored version, however, works because you can't hear Renfield).