I know this may not be a bombshell to most "Star Wars" fans, but James Earl Jones was not in the Darth Vader suit at the time of filming. For the eight people who didn't know that, sorry to ruin the illusion. But c'mon, we've all seen James (or as I think of him, the blind guy from "The Sandlot") -- I don't care how not fat he was when he was younger, there's no way he's fitting in that suit and lording over the Galactic Empire with any authority. The Jabba suit, perhaps, but certainly not Vader. (Please excuse the cheap shot, but James Earl Jones would've killed in that role.)
Since Jones's voice was dubbed in later, David Prowse, the English actor and body builder (thanks wikipedia) inside the suit, could be heard saying the lines during the actual filming. Wondering what Prouse looked like? Check him out on left. Not so imposing. Kind of looks like a guy who went to a "Star Wars" convention and tried on the suit while everyone was distracted by a conversation about how "'The Phantom Menace' isn't that bad when you lower expectations."
But for all those fanboys (myself included) hankering for what the original Vader sounded like, check out the video below. This is actual footage from the filming of the first movie. Not really the menacing voice of a Sith Lord, or a body builder for that matter. But he delivers the lines with such gusto. Such fervor. Too bad he sounds like a 10 year old in basement playing with plastic light sabers.
The movie would have been a lot different if Prowse's original dialogue had made the final cut. Vader's not so scary with a wimpy, British accent.
And just to compare (and make you appreciate James Earl Jones even more), here's a clip from the final cut of movie. (Via WhoseVoice.Org)