The second shot in Pulp Fiction, Quentin Tarantino's bloody pageant of life in Los Angeles, is a tight close-up of a waitress asking Tim Roth and Amanda Plummer "Can I get any one more coffee?" They're in that diner, just before they try to rob it.

It's not just a close-up; she leers up out of nowhere, forcing herself into the frame. QT is telling us to wake up: he is about to show us new tricks. Another director might have covered the coffee pour without cutting – the waitress could have entered the wide shot and poured and disappeared without us seeing her face. Instead, Tarantino takes the most powerful shot in the arsenal of a film director and blows it on a coffee call. Why?

Let's back up. In classical Hollywood cinema, the close-up is a climax shot – and I do mean that both ways. Classical editing moves from wide shot to establish the geography of the scene, then a series of cuts take us closer to the action, each one communicating more information and drama.

The classical director reserves a close-up for when he or she wants to pair the emotion to the character in a strong way. One of the most beautiful close-ups is in Casablanca, when Ingrid Bergman asks Dooley Wilson to play As Time Goes By. After he plays the first bar, we cut to her face in a close-up that makes strong men go jelly in the belly. By close-up, I mean from just below the chin to just above the hair.

Before this we have a series of ravishing shots of Ingrid in medium close-up, showing her from chest up. These start the seduction process between actress and camera, but the close-up seals it – a director's kiss. She is so beautiful, and so beautifully lit, that the audience feels they've had their money's worth already. If movies are indeed sublimated sex, then the close-up is… well, let's not be indelicate. Casablanca is perhaps the world's best close-up movie – after the initial set-up, they just keep coming, a series of stunningly emotional close-ups to die for.

This kind of shot is rare now. It's been replaced by the space invaders. Directors now go in close early and stay there, even in wide-screen ratios. It makes watching a modern film painful for older viewers, but youngsters seem to like it. Fast editing, fast lives, close shots.

Hollywood directors before 1950 rarely entered the close space around an actor unless for good reason. That was the golden rule of directing: every shot, every cut, must advance the storytelling. Going in close when the movie screen was perhaps four or five metres high could make the faces too big, so most used it sparingly.

Everything changed with TV. It required close-ups all the time, so that the faces would be big enough to read.

People now watch movies on their phones – which is like dancing in your closet. Why would you want to? The pressure from producers to go in closer is ever stronger. The problem is the more you use the close-up, the less powerful it becomes, unless you use it well.

Tarantino, like Martin Scorsese and Sergio Leone before him, is a master of the close-up. He shows us the coffee waitress in that scene as a sort of in-joke, a reference to the first scene in Reservoir Dogs, when Steve Buscemi​ refuses to leave a tip and the other gangsters try to convince him that low-wage waitresses need tips. Those guys would never have dreamed of robbing a diner. No class.

It also makes sense to show the waitress in close-up because it makes everything more personal: Roth and Plummer are robbing her, not just anybody. Invasion of personal space is part of what this movie is all about, so QT has about 10 different variations on a close-up. He has the comedy close-up, the fear close-up, the overdose close-up, the cocaine-sniffing close-up, the upside-down on the floor close-up. Pulp Fiction is a compendium of the modern close-up. That was part of what people responded to. Even if we didn't notice them, it felt different, just as in Scorsese's Goodfellas and Casino before it. These directors had learned all the rules of the medium before they broke them. Their close-ups respected the power.

With lesser directors, the close-up means nothing. If they were grenades, these guys would have no hands. In modern action, particularly those films involving robots and super-heroes and men in tights, the close-ups are often just hero shots. Typically, the camera rushes in to a tight close up as someone delivers a sassy line. Blame Clint Eastwood and Arnie Schwarzenegger, who established the power of three-word tag lines combined with a medium close-up. I'll be back. Make my day. Shoot me now.

Clive James wrote in his book Fame in the 20th Century that the close-up is part of what established the cult of celebrity. Once the close-up was invented around 1900, it led to the creation of screen stars. The faces really were big, to misquote Norma Desmond, and they gave us a new sense of intimacy with people we'd never met. We've devalued that power with overuse and new screens.

Close-ups have become commonplace. But the art is not dead, only sleeping, like the blue parrot in Monty Python. I pine for its return.

On twitter: @ptby­­rnes