Lights, camera...type!

If you are old enough, you may recall a much-seen short film from the mid 1980s.

It begins with shots of the Lake District – mighty fells, ominous cloud formations, plashing waterfalls. Elgar flows nobly on the soundtrack, and then is joined by the posh tones of a man declaiming: "I walked around a bit on my own ...." The fellow breaks off, sighs, starts again. "I strolled about without anyone else ...." Breaks off again. "Oh dear, oh dear ...." Finally, we see the chap himself, supping an al fresco pint. Elgar swells in triumph, and so does his voice: "I WANDERED!!!, lonely as a cloud that floats on high ...". And then comes the pay-off to this lager commercial: "Heineken Refreshes the Poets Other Beers Cannot Reach".

An amusing sales pitch; and also, in its modest way, one of the most accurate films ever made about the actual business of writing poems – a business which demands hour after hour of sitting quietly on one's own, fiddling with words until they come more or less right. Julien Temple's film Pandaemonium, a much more sombre take on Wordsworth and his youthful oppo Coleridge, uses exactly the same conceit as the witty lager ad: "I wandered lonely as a cow", Temple's Wordsworth ventures at one point. His sister, Dorothy Wordsworth, suggests that a cloud might be classier.

Even the most supposedly "spontaneous" of poets have been chronic textual tinkerers, though they have tended to be discreet about the habit in case it tarnished their image. Whitman, a wild and impulsive bard if ever there was one, revised "Song of Myself" through edition after edition; while Whitman's 20th-century counterpart, Allen Ginsberg, sweated for hours at his typewriter to craft his breakthrough work, "Howl", as the lavish annotated edition of 1986 showed. Some of Ginsberg's fans were dismayed at this revelation: the assumption that Ginsberg simply opened his mouth and let the universe speak through him used to be a Beat truth universally acknowledged. The English poet Clive Wilmer recalls once going into the lavatory at a 1960s poetry reading and laughing at the cruel graffiti: "Ginsberg Revises!"

Ginsberg is the hero of a forthcoming biopic, Howl, which stars James Franco – who, by the way, catches the poet's idiosyncratic speech patterns with admirable precision. It's easy to see the appeal of Ginsberg for film-makers. His life was crammed with incident – love affairs both gay and straight, a spell in a mental hospital, intense friendships with Kerouac and other Beats, and a juicy obscenity trial. Ginsberg was also the first famous poet to deliver his works with the volume, intensity and passion of a bebop sax solo. The film's sequences of Ginsberg belting out "Howl" to coffee-house audiences shows how thrilling it must have been to hear him when the poem was still new. (On a personal note, I once filmed the middle-aged Ginsberg reading "Howl" to an audience of professors at a literary conference in New York. It was about as wild as a Women's Institute evening.)

And when it comes to showing Allen in the throes of composition ... well, there is a kind of gentle thrill in seeing someone furiously beating up their typewriter in search of precise phrases. That mechanical era is past, and poets who work on laptops will, for the most part, no longer leave a rich paper trail of their revisions for the scholars to ponder. But the new movie about Ginsberg and company is an honourable exception to the otherwise general rule that poets on film still go in for pen, pencil or quill. And are hardly ever seen to scratch out words or stanzas.

For example, take a shufty at the notebooks of Janet Jackson's character in Poetic Justice (incidentally, a strong contender for the title of silliest film ever made about a poet). She writes in pencil; and the pages are utterly clean, with not so much as an altered comma. Zero out of 10 for plausibility, though the filmic convention is forgivable. We tend to say that extremely boring experiences are "like watching paint dry"; but watching paint being applied to canvas and drying on the big screen can sometimes be an exhilarating thing, as in Scorsese's Life Lessons, or – a more extreme version – in Jacques Rivette's La Belle Noiseuse. If you sat in a cinema watching some equally sedentary man or woman scribbling in silence for two hours, you might well start to hunger for the raw excitement of a paint-drying sequence.

Painting, sculpture, music, drama, architecture, dance and film-making itself: all are eminently well-suited to certain types of screen adaptation, and often fairly accurate adaptation at that: think of Lust for Life, Savage Messiah (and lots of other Ken Russell films), Topsy-Turvy, The Belly of an Architect, The Red Shoes, Day for Night. But the creation of poetry eventually boils down to a sheet of paper and a pen. To be sure, films about poets can and do strive to provide adequate visual counterparts to their words. This is a long and distinguished tradition – Auden's verses in Night Mail, for example, or Blake and Milton in Words for Battle, by Humphrey Jennings, himself a poet. It takes uncommon talent, though, to do this in ways which do not seem either like a redundant spelling-out of a poem's literal sense, or an irritating irrelevance.

Faced with this obstacle, film-makers have tended to take the fact of poetic composition more or less for granted – or to leave it out entirely – and to opt for more colourful details from Lives of the Poets. This is a crowd-pleasing option as well as an easy one, since in the popular imagination the very word "poet", when it does not imply someone who is utterly wet and a weed, still tends to summon up a wild boyo like Dylan Thomas rather than a boring insurance executive like Wallace Stevens, a spat-wearing banker like Eliot or a grumpy librarian like Larkin. A short roll-call of examples, including both the sublime and the daft:

Drunks and drug fiends

Samuel Taylor Coleridge (Ken Russell and Pandaemonium); Dante Gabriel Rossetti in Russell's television film Dante's Inferno; Charles Bukowski in Barfly (Mickey Rourke) and Factotum (Matt Dillon); Dylan Thomas (Matthew Rhys) in John Maybury's The Edge of Love; Dorothy Parker (Jennifer Jason Leigh) in Mrs Parker and the Vicious Circle; Michael Caine's alcoholic teacher in Educating Rita.

Martyrs, rebels and weirdos

Arthur Rimbaud (Leonardo DiCaprio) and Paul Verlaine (David Thewlis) in Total Eclipse; Reinaldo Arenas in Before Night Falls; the nameless protagonist of the justly neglected British avant-garde Herostratus; T S Eliot (Willem Dafoe) in Tom and Viv; Gwyneth Paltrow as Sylvia Plath in Sylvia (Daniel Craig played Ted Hughes).

Swashbucklers, lovers and romantic heroes

David Niven's Marvell-quoting fighter pilot cum poet in A Matter of Life and Death – not only one of Powell and Pressburger's best films, but one of the best British films ever; Fredric March as Robert Browning and Norma Shearer as Elizabeth Barrett in The Barretts of Wimpole Street; William Shakespeare in Shakespeare in Love; Depardieu as Cyrano de Bergerac; Fabrice Luchini as Molière, Byron in Bride of Frankenstein (a whimsical delight by James Whale), The Bad Lord Byron (Dennis Price), in Lady Caroline Lamb (Richard Chamberlain) and Nikos Koundouros's Byron; John Keats in Jane Campion's Bright Star.

By no means a contemptible list, though it shows how selective the poet-picking has been. Novelists and dramatists, in their less expensive media, have ranged wider and aimed higher: Milton has been the subject of at least one novel, as has John Clare, and Virgil, and countless others, including the Roman dialect poet Belli (in Anthony Burgess's novel ABBA ABBA).

There are some other poets whose lives have been so extraordinary as virtually to scream out for the screen: Ezra Pound's, for example. Pound's imprisonment by the US Army for treason at the end of the Second World War offers not merely gripping drama but a chance to ponder questions that go deep to the heart of poetry. When does a word become a deed? (Perhaps when, like Pound, one uses the broadcasting services of an enemy nation, Italy, to transmit messages urging disaffection on Allied troops.) Can poetry sometimes be literally – not just in a Powell/Pressburger film – a matter of life and death? Not everyone's beaker is full of the warm south; yet poetry is surely preferable to yet more bardic boozing and wenching.

The greatest representation of a poet on film is surely Cocteau's Orphée, with its brilliantly simple metaphor of poetic inspiration as cryptic messages from the Underworld, heard on a car radio. We do not hear any of Orpheus's own verses, and we don't need to hear them. The film itself is a poem.