Dear Nicolas Roeg,

So you’re thinking of coming to Edinburgh. Will you travel up from London by train? I imagine you staring out the window as England whizzes past in Turner blurs and Constable clusters. Do you still look at landscapes as the cinematographer you once were, Nic? Are the train vistas today epic and sharp, like your photography in Far From the Madding Crowd? Do you still like looking at landscapes or, after 62 years in film, are you all looked out? Does there come a point when you’ve seen everything?

When you get to Edinburgh, might you go to the Camera Obscura, near the castle, where your old mate Donald Cammell was born? How appropriate that it is a hall of mirrors, holograms and trompe l’oeils now, given that Performance, the film you made with Cammell, your first film as a director, was a masterpiece of tricks of the eye and brain.

I imagine you sitting on the right of the train as it passes close to the North Sea in Northumberland. Maybe it stops and you get to stare at the waves, Nic. How often your films stared at water. I’m thinking of Jenny Agutter swimming naked in Walkabout. In adult life I haven’t once worn swimming trunks. The blue remembered hills in Walkabout convinced me that naked swimming is the only decent thing. After Walkabout, of course, came your movie Don’t Look Now, with its Venetian water courses and that incredible baroque drowning of the girl in red at the start. Water by then had become one of your great image systems, hadn’t it? And in Don’t Look Now, as Donald Sutherland wandered around Venice, we saw that the city was a labyrinth, one of many in your films, those mazes that amazed us. I studied your work at the University of Stirling, the first university in the world that taught you properly, I think.

Our lecturer was John Izod, who told us about mazes, mandalas and Jung. He showed us that your movies are as great as Wordworth’s 'The Prelude', as Bowie’s Hunky Dory, as Walt Whitman’s Leaves of Grass, and he was right. You and your screenwriters showed our young minds that our lives would not be linear. And you were right. I once spent a day with Donald Sutherland; we watched the sex scene in Don’t Look Now and drank wine – a double delight for me, but what struck him as he watched himself roll around naked on a bed with Julie Christie was that his wig looked good.

Sex, Nic. As your train crosses the border into Scotland, a place where sex is heard but not often seen, I imagine that there’s a woman sitting opposite you on the train. Do you glance at her and look away? Has she a catch in her throat? Are you strumming your fingers on the table between you? When you look at the woman opposite does your mind flood with what Robert Louis Stevenson called 'a thousand coloured pictures to the eye'? Do you see Theresa Russell in the woman, and your other lovers? Do they come to you in flashes, Nic, like the close-ups of Theresa’s brooch in Bad Timing, a film you made after Don’t Look Now, which was even more about Eros and Thanatos than your gothic Venetian film? You had us in Bad Timing’s opening Tom Waits song, 'Invitation to the Blues', Nic, especially the line 'from her cunt down to her shoes.' What an invitation to the blues your cinema is, Nic. Maybe your glances to the woman on the train are another such invitation. On sex, Nic, it’s as simple as this: you made it new in cinema. By using cutting, you and your editors made sex cutting.

And it’s time to talk of time, Nic. In Don’t Look Now and Bad Timing in particular, sex seemed like a black hole that sucked time in. Donald Sutherland’s and Julie Christie’s bed was like a time machine – we saw the sex and the getting dressed at the same time – and, in Bad Timing, Art Garfunkel did something in the name of sex that seemed to break the space-time continuum, that fragmented the story into shards. Harvey Keitel came rushing in to the story like Dr Who, all intuition and otherwordliness. The characters in your films – James Fox in Performance, Agutter in Walkabout, Sutherland in Don’t Look Now, Garfunkel in Bad Timing – seem to look at themselves in the mirror and say 'Candyman' three times, calling forth their tempest.

To say this makes me imagine you on your train, with the landscape, the water, the woman, catching a glimpse of your reflection in the window. What do you think when you, the great artificer, see yourself? Do you think of Rutger Hauer’s Claude Maillot Van Horn character in your film Eureka who, when he sees himself in the mirror, says to his reflection 'I thought it might be you'? He’s disappointed, isn’t he? He just can’t escape himself, he longs for the rapture of self-loss. Are you disappointed by what you see, Nic? In your eighty-fifth year, you’ve travelled each and every highway.

When you glimpse your reflection in the train window as it’s getting into Waverley station, some of us would like to tell you that what you see is someone who means more to us than Charlie Chaplin or Akira Kurosawa. Step off the train knowing that your best movies speeded us through the process of learning about living.

When you get to Edinburgh, might you go to the National Gallery? There’s a painting there, Paul Gauguin’s 'Vision of the Sermon', in which seven women, standing behind a tree, look into a red-brown field and see an angel wrestling someone (I think it’s Jacob). Those women are seeing life, Nic, something amazing, in a different realm. We, your fans, are those women. We watch as your movies wrestle with life and art.

With best wishes,

Mark Cousins

The World is Ever Changing is published on Thu 18 Jul by Faber and Faber.