Chiwetel Ejiofor

Can you bring it down a notch, Bill?

As an actor, Chiwetel Ejiofor likes directors to be gentle with him. Would it work when he came to direct his first film?

Iain Glen has disappeared into a cloud of dust. Three men are kicking and stamping on him, and it looks pretty convincing. I’m watching all this on a tiny monitor, in an underpass by the canal in Hackney Wick, London.

It’s our final day of filming. The action is in silhouette, and the colours, the cinematography, everything is just as I imagined - even better - but something isn’t quite right. I study the monitor and shout, "Cut!"

Everything stops: Iain gets up, and someone rushes over to give him a glass of water. His attackers move away slightly to catch their breath. I’m a little stumped, to be honest. What was wrong with that take? Something.

Definitely something. A slight expectation hangs in the air. This is the bit when I’m required to do some actual directing.

Directing is a job I’m very new to. In terms of shooting, I’ve been at it for about five days. In terms of pre-production, just over a month, but I feel pretty comfortable and at home. Right now, though, I can’t put my finger on what it is I want to change. We’re shooting the last sequence of a short film I wrote, called Slapper. Time is tight, it’s just gone midnight, and we have plenty left to do. I pull off my headphones and walk over to the guys. "Really good," I say, "it just needs ... more."

It might sound a little coarse, but as an actor I’ve always liked this kind of directing. I like simply being asked to do more or less, to do it louder or softer, faster or slower. Many times, this kind of direction just works. Also, I don’t know what else to say, so I don’t try to refine it any further. Besides, these are great actors, who really sell the physical side of the story, so I feel that this time it could just all slot into place.

I pull the headphones back on and shout, "Action!" Iain disappears again into a cloud of dust. The guys kick and stamp. There is more enthusiasm this time, but perhaps it’s a little too chaotic, a little too heightened. "Cut." This time, I’ll need to give some specifics. There’s pressure to get to the next sequence, but I don’t think we’ve finished here yet.

It’s hard to know how much being an actor has helped with my directing. What I’ve loved most about this process is turning fiction into fact; the entire five-day shoot has felt like existing on that plane of consciousness where the real meets the imagined.

A few years ago, a director once opened a scene up beautifully, by telling me quietly to hold the other actor. "Hold her," he whispered to me. "Not physically, you understand - just hold her." Magic. Anyway, here I am with nothing as nuanced to say, not telling anyone to hold anyone. Instead I’m saying, "Maybe you can stamp on his head from this angle. I think if you stamp on his head from here it’ll look better."

This film was dreamed up in my friend’s garden in Brixton a few years ago - all these characters, these locations, even me with the headphones, staring at a monitor. It was just a question of making an imaginative leap, and here we are, a few sequences away from having the film in the can. "Action!" Dust, a disappearing Iain Glen. "Cut." What is it this time - is it the shot? I don’t think so: the shot itself looks great. Is it the performances? No: I mean, they look as if they are kicking the living daylights out of this guy. So why am I still not happy with this shot?

I look at Baz, the cinematographer. He nods, indicating he’s very happy and ready to move on, but I can’t. I head on back to the actors. "Let’s make the violence a little more staccato," I say, "a little less balletic." They look at me like I’m nuts (balletic is not the word for these guys), and I realise the problem is me. It’s the last few moments of shooting a script that I’ve kicked around, toyed with, got serious about, finally written and am loving making.

I realise I’m dragging this out. I’m holding on. "One more time," I say.

Iain gets on the filthy ground. As I put the headphones on, I hear him say, "I think Chiwetel’s enjoying this a bit too much." The others laugh. Actors: they’re so smart.

· Slapper screens on June 24 as part of the UK Shorts programme at the Edinburgh film festival.