With the box office success of Cloverfield, a lot has been written about the film’s shaky, hand-held camerawork, which has drawn comparisons to The Blair Witch Project, and the monster being unseen throughout the film, which some of the best horror films in history have done as well.

Keeping the monster hiding in the shadows is certainly nothing new in cinema. Two of the best classic examples are the films of Val Lewton (Cat People), and the original version of The Thing from the ‘50’s. It’s never been explained exactly why master filmmaker Howard Hawks decided to show the Thing late in the game when many directors would have shown it throughout the movie, but Hawks’ biographer Todd McCarthy believes it was due to his shrewd storytelling sense.

“Knowing Hawks’ intelligence and shrewdness about these things, I’m sure that’s what it was,” McCarthy says. “Certainly in a lot of those ‘50’s films, if you showed the monster too much, you could see how phony it was. That could have played a role, but I think it was just shrewd storytelling. Hawks always went for understatement as well, and would shy away from anything that would have led him to show it more blatantly.”

One of the most cited modern examples is Jaws. The mechanical sharks that were built for the film kept breaking down, and Spielberg was forced to show the shark less than he initially planned. It was an enormous headache during the shoot, but it turned out to be a blessing in disguise.

Carl Gottlieb, the screenwriter of Jaws, says, “Steven and I were both impressed by The Thing as young moviegoers, and we knew (hiding the monster) was a valuable device. We couldn’t show the monster, we didn’t have a monster! If we had a full budget for the shark and the shark was working, you would have seen much more of it. It may have been problematic in it wouldn’t have been as effective of a movie, but I would give Steven credit enough that if we had a shark for all the shots we needed a shark for, I think we would have created an equally terrifying movie, we just would have gone about it in a different way.”

In the documentary The Universal Story, Spielberg said, “By the shark not working, it allowed me to be much more experimental and find a way to make the surface of the water and the threat of the unseen as powerful as having seen the shark too early. I think the film would have made half the money had the shark worked.”

Alien also got a hell of a lot of mileage out of keeping its monster hidden for most of the film. “There are many good reasons for that, just as a simple dramatic principle of writing something scary, the unknown is the most frightening thing,” says Alien screenwriter Dan O’Bannon. “Make the audience squint, stare and try to catch glimpses of the thing in the shadows. Underexposure is always more effective than overexposure when you’re trying to scare people.”

“That’s what made Alien scary,” says legendary make-up effects artist Tom Savini. “If you showed the creature early in the film, the audience reaction would have been, ‘Oh, that’s it? I can take that,’ because they’d know what the threat is. By not showing it, you leave them in a state of confusion.”

When Roman Polanski decided not to show the infant spawn of Satan in Rosemary’s Baby, the film’s producer, William Castle, was certain the audience would feel burned. “Of course,” Polanski replied. “But I don’t think we should ever let them (see it). On the contrary Bill, everyone will have his own personal image. If we show our version—no matter what we do—it’ll spoil that illusion. If I do my job right, people will actually believe they’ve seen the baby.”

As Castle recalled in his autobiography, “Polanski was right. Many people leaving the theater believed they had seen Him. When Rosemary was shown on TV, columnists reported that ‘due to censorship,’ ABC had cut the scenes where the ‘baby’ was shown. Rosemary’s ‘baby’ was never photographed.”

This doesn’t just apply to horror films. Quentin Tarantino certainly learned a lot about making movies from the horror genre, and used what you imagine is worse than what you can see to great effect in Reservoir Dogs. As Christopher McQuarrie, screenwriter of The Usual Suspects, said at a seminar for Fade-In Magazine, “You hear people talk about Reservoir Dogs, this torture scene that was so horrible and so brutal... but they shot a wall. They started cutting his ear off, and then they panned away. And I’ve heard people vividly describe this brutal torture scene that isn’t there.”

Then Tarantino applied to same principal to one of the classic elements of Pulp Fiction. When I interviewed Tarantino’s former writing partner Roger Avary for Creative Screenwriting, I asked if there was definitely something in the suitcase, or if it was intentionally not shown so the audience would be left guessing. Well, he wouldn’t say exactly, but he did say that the suitcase was originally going to have the diamonds from the Reservoir Dogs heist. This idea was quickly abandoned, because “it’s not fantastic enough,” Avary said. “Nothing is fantastic enough. The only way to make something truly fantastic is to not tell people what’s in it, then it’s different for every person in the audience.”

Brian DePalma once said the key to suspense was withholding information. How much you show, or don’t show, in a horror film is ultimately up to the filmmaker’s taste, or lack thereof. As Anthea Sylbert, the costume designer on Rosemary’s Baby, says, “I believe in all good films, and indeed in all good art, you have to know what to leave out, what to eliminate. It gives importance to what you include.”