Directors' images that wax and wane

It may now seem hard to credit, but there was a time in the late 1940s when, on the strength of Odd Man Out , The Fallen Idol and The Third Man , Carol Reed was seriously proposed as the greatest film director in the world. But from then on his reputation plummeted via a succession of misconceived projects at home ( The Man Between , A Kid for Two Farthings , The Running Man ) and in Hollywood ( Trapeze , The Agony and the Ecstasy ). In 1968 the tuppence-coloured cheeriness of Oliver! won him an Oscar but little critical kudos, after which his career dispiritingly fizzled out with a pair of forgettable flops.

As Reed's star has fallen, the twin suns of Michael Powell and Emeric Pressburger have risen. In the 1940s, the decade of their finest films, the pair were regarded with some suspicion by the critical establishment because their flamboyant romanticism was defiantly at odds with the documentary-style realism then reckoned the benchmark of cinematic quality.

Twenty years on, with their partnership dissolved and Powell driven abroad by the howls of execration that greeted Peeping Tom , their reputation went into eclipse. But since then, extolled by champions such as Ian Christie and Martin Scorsese, their stock has appreciated to the point where Andrew Moor can hail them, without running much risk of contradiction, as "the most remarkable and visionary (partnership) in British cinema".

Moor concentrates almost entirely on Powell and Pressburger's glory years, from their first film together ( The Spy in Black , released in 1939 just before the outbreak of war) to the pair of musical extravaganzas ( The Red Shoes and Tales of Hoffmann ) that marked the height of their joint ambitions. The relatively disappointing productions of the 1950s ( Gone to Earth , Oh... Rosalinda! , Ill Met by Moonlight and so on) come in for only passing reference, and the films they made independently of each other fall outside the book's scope.

Peter William Evans, by contrast, conscientiously covers almost the whole of Reed's directorial career, though even he draws the line at devoting space to that final pair of turkeys.

Evans's study, one of the monographs in Manchester University Press's series British Film Makers, takes issue with the common perception of Reed as a director without personality, most brutally expressed by the film critic David Thomson: "Reed is a characterless director, so personally unobtrusive that his style takes on the surface colouring of whatever company he keeps." Evans never quotes Thomson's dismissive verdict, but one senses that it was rarely far from his mind. Drawing on psychological models, he traces "unmistakable idiosyncrasies of form and content", recurrent themes and preoccupations that crop up throughout Reed's work.

Parent-child relationships, he notes, feature strongly, often in terms of an absent parent or parental figure associated with a sense of rootlessness or social isolation. Reed, he notes, is drawn to outsiders, self-destructive protagonists whose search for identity and emotional reassurance usually leads to disaster - for themselves or for those they become attracted to. In this reading, the world of Reed's films is essentially pessimistic, one whose settings "are all 'uncanny' spaces offering little or no comfort to their troubled men or women, projecting the inner torment of their marginalised inhabitants", with Reed himself "the poet of alienation".

Now and then, as if with a view to adding weight to his thesis, Evans lets himself be sidetracked into irrelevant disquisitions. An account of Climbing High , a bizarre early work that finds Reed rather improbably directing Jessie Matthews in - among other things - a custard-pie fight, swerves off into a potted history of Hollywood romantic comedy; and later, in the chapter dealing with Odd Man Out , we are treated to a lengthy quotation from Nietzsche simply to demonstrate that there is nothing in the least Nietzschean about the film's protagonist, IRA activist Johnny McQueen. These lapses apart, though, Evans argues his case cogently, and makes a good case for a director now as unduly underrated as he was once extravagantly overrated.

Powell and Pressburger, if anything, may now be in danger of tracing the opposite trajectory. Moor, though, is a frank admirer of their work, and at first sight his study offers a thoughtful addition to the literature on the symbiotic duo. In his opening chapters, he proposes a reading of the films in terms of territory - both physical and psychological - noting their preoccupation with borders, divided loyalties, shifting national identities and nostalgia for lost homelands. These are the "magic spaces" of Moor's title, akin perhaps to A. E. Housman's often quoted "land of lost content" ("The happy highways where I went/ And cannot come again"), and he plausibly links them to the status of the film-makers themselves - the Hungarian Jewish Pressburger, a literal exile, and the Englishman Powell at odds with the prevailing cinematic culture, a self-styled romantic who always saw himself as a "loner".

This is a fruitful line of inquiry, which makes it all the more regrettable that, after a certain point, Moor seems to lose the thread of his argument. The chapters on the postwar films - roughly from Black Narcissus onwards - are noticeably less considered, less tightly argued and often bulked out with chunks of elementary-level social history. ("Rationing continued, and the weather was dreadful.") Whole sentences, and even paragraphs, are repeated almost verbatim, and the book ends abruptly, with no attempt at a summing-up or a conclusion. The dread phrase "urgent publisher's deadline" irresistibly presents itself.

Philip Kemp is a freelance writer and film historian, who teaches film journalism at Leicester University.