It has always been hard for sitcom stars to make the transition to movies. Despite the occasional hit, the members of the Friends cast have struggled to carve themselves film niches and it seems clear from Liberal Arts that Josh Radnor finds it equally difficult to leave behind the character of Ted Mosby he has played for seven years in the smart Manhattan series How I Met Your Mother. Yet, while it reinforces Radnor's affable screen presence, this second outing as writer-director after Happythankyoumoreplease (2010) confirms that he also has an ear for dialogue and an eye for a photogenic detail. However, he still has a long way to go to match the wit and insight of Woody Allen and Whit Stillman, whose work this amiable romcom irresistibly resembles.

Bored with his job as a New York schools admissions officer, 35 year-old Josh Radnor is so deep in a state of ennui that he almost doesn't notice that live-in girlfriend Kristen Bush is dumping him and that bookseller Elizabeth Reaser has a crush on him. He can barely summon the energy to chase the thief who steals his washing from a launderette. Yet, when old professor Richard Jenkins invites him to Kenyon College, Ohio to speak at his retirement dinner, Radnor leaps at the opportunity and cannot get out of his rental car fast enough to inhale the intoxicating air of the campus where he spent the best years of his life.

At lunch, Radnor meets Jenkins's friends Robert Desiderio and Kate Burton and quickly becomes enchanted by their 19 year-old daughter, Elizabeth Olsen, who is studying literature and performing with an improv troupe. Pleased with himself for getting her stage mantra that the answer to every question is `yes', Radnor attends the dinner feeling unfamiliarly upbeat. But his mood is soon doused by Jenkins's valedictory bout of self-pity and he takes a moonlight walk to clear his head. He tries to avoid engaging in conversation when he bumps into zoned out slacker Zac Efron, but winds up following him to a student party where he flirts with Olsen and makes a date for coffee the next morning.

While waiting for Olsen, Radnor makes the acquaintance of John Magaro, an intense but insecure undergraduate who is reading David Foster Wallace's Infinite Jest. Radnor warns him that reading can become a treacherous solace for the lonely and that he needs to seize the opportunities around him. Indeed, this becomes the theme of his conversation with Olsen, as they stroll between Kenyon's chapel and theatre and come to realise that, in spite of the age difference, they have a lot in common. Yet Olsen seems far more mature than Radnor and feels that he views youth with rose-tinted nostalgia and should stop fretting about unfulfilled potential and start living in the present.

Stung by beloved English tutor Alison Janney failing to remember him, Radnor is rescued from another funk by Olsen giving him a CD full of her favourite pieces of classical music and he readily accedes to her request for a hand-written letter of thanks. In fact, they begin corresponding regularly, with their voiceover missives being accompanied by snatches of Beethoven, Wagner, Vivaldi and Massenet over a montage of images showing Radnor rediscovering his love for life and growing affection for Olsen. Thus, when she suggests he visits her at Kenyon, he is powerless to decline (even though the scribbled calculations on a notepad confirm his suspicion that this May-September liaison may not be entirely wise).

As Radnor fights down feelings of trepidation, Jenkins pleads with boss Gregg Edelman to let him withdrew his resignation and teach on for another three years. However, a successor has already been appointed and Jenkins has to accept that his day is done. Across the campus, Radnor begins to have doubts of his own, as he has an argument with Olsen about her love of Twilight-style vampire fiction. He spends the afternoon with the worst book he has ever read and becomes increasingly irate that somebody he admires should consider that it has even an iota of intellectual validity.

Their row is interrupted, however, when Jenkins spots them in a bar and lectures Radnor on the folly of having a relationship with someone so vulnerable and so much younger. Shortly afterwards, Radnor encounters Efron again under the stars (and wonders if he is not a figment of his imagination in his Peruvian knitted hat) and his prattle about caterpillars having to fight off all sorts of internal obstacles in order to become a butterfly convinces Radnor to knock on Olsen's door. With roommate Ali Ahn already dispatched for the night, Olsen tells him that she wants him to be her first lover. But the responsibility proves too much for him and he bolts, leaving her to seek solace in hunky classmate Ned Daunis, while he allows himself to be seduced in a bar by the predatory Janney, who throws him out of bed the moment her lust has been satiated and mocks his naive belief that they would cuddle in the warm afterglow and read poetry to one another.

Back in New York, Radnor acknowledges that he has some growing up to do and asks Reaser to go for a walk. However, he isn't quite done with Kenyon, as Magaro phones to confess to taking an overdose of pills and Radnor has to overcome his fear of flying to sit by his bedside. Having made his peace with Olsen, Radnor returns east and snuggles with Reaser as she muses about how nice it will be for them to grow old together.

Notwithstanding the chauvinism that undermines the depiction of Olsen, Janney and Reaser's characters, this is an enjoyable dramedy that has little new to say about thirtysomething angst, but says it eloquently and amusingly. Radnor's visual style is rather bland, but cinematographer Seamus Tierney lovingly captures the allure of Kenyon (which is Radnor's real alma mater) and the cast makes being bright, curious and well read seem desirable - which, sadly, is rarely the case in many modern British movies. The script loses its way periodically and neither the Magaro nor the Efron subplots works at all. Yet, even thought the Jenkins and Janney strands feel a tad tangential, each has a standout scene in which they redeem themselves.

As for Radnor the actor, he contents himself with slipping between Ted Mosby and an older version of the character he played opposite Kathleen Turner in his Broadway debut, The Graduate. But he creditably manages to prevent the romance with Olsen from feeling too inappropriate, although this has as much to do with the fact that, at 22, she always seems too mature and wittily wise to play a teenage virgin with a taste for trash fiction. Nonetheless, they spark charmingly and it's a shame that the chemistry between Radnor and Reaser is so palpably less potent, as the contentment she feels at the thought of ageing with someone she truly loves makes this one of the sweetest happy ever afters in recent American cinema.

As unlikely as it may seem from its title, Jack Perez's Some Guy Who Kills People runs it pretty close. Boasting some of the year's quirkiest dialogue, Ryan Levin's screenplay contains several laugh out-loud moments and it's quibbling somewhat to criticise the Scooby-Dooesque revelation of the culprit. Executive produced by John Landis, this is almost certainly destined for instant cult status. Moreover, if there is any justice in Tinseltown, Barry Bostwick would land an Oscar nomination for Best Supporting Actor for his crackingly eccentric turn as the small-town sheriff confronted with a killing spree.

Released from an asylum 11 years after trying to commit suicide, 34 year-old Kevin Corrigan works with twitchily loyal school pal Leo Fitzpatrick at Lou Beatty, Jr's ice-cream parlour in the town of Green Oaks, which is famous solely for its annual owl festival. Swarthy and taciturn, Corrigan lives at home with sneering mother Karen Black and hides away in his room scrawling in notebooks and enduring nightmares about being beaten up by high-school basketball jocks Britain Spellings, Christopher May, Niko Nicotera and Jonathan Fraser, who had taken exception to their depiction in a comic-book he had drawn.

Thus, Corrigan is far from dismayed when the obese Spellings is murdered after his birthday party and is left sitting in a petrol-soaked garden chair holding a pair of playing cards. Sheriff Barry Bostwick and his dullard deputy Eric Price reach the scene of the crime with little enthusiasm and are scarcely surprised to hear widow Lindsay Hollister celebrating her cheating spouse's demise. Few shed any more tears when the drug-addled May is decapitated at the drive-in and has a V carved into his back and the lollipop-sucking Nicotera is deposited in a bath of his own blood in the middle of the local skateboard run. Indeed, Bostwick treats each slaying as an opportunity to make puns or comment on the Dadaist disposition of the corpses. Besides which, he openly discusses the case at the dinner table when he calls on Black for a little off-duty TLC.

Corrigan is somewhat distracted from the furore, however, by the sudden appearance of his 11 year-old daughter Ariel Gade. Furious with mother Janie Haddad and God-bothering stepfather Regan Burns for lying to her that her dad was dead, the garrulous Gade moves in with Black and Corrigan and sets about matchmaking him with Lucy Davis, a tongue-tied British exile whose marriage to a Harvard egghead had been a disaster. Gade also tries to convince Corrigan that she is the star player on the school basketball team. But, when he calls at the gym to collect her, he sees that she is being bullied by the popular kids in just the same way that he was 15 years earlier.

Shortly after Fraser is found murdered in his army surplus store, Bostwick notices some cut-up magazines in Corrigan's car. So, with mayor Ahmed Best pressurising him to make an arrest, he reluctantly reaches the conclusion that Corrigan must have been sending him the anonymous notes taking credit for each killing. But, no sooner has he put him behind bars than Bostwick sees a card that Gade made for Black from cut-up lettering and realises who has really been responsible for all the carnage.

Splendidly low-key in its offbeat blend of bleak comedy, domestic dysfunction, police procedural and good old-fashioned hick slasher, this may stick closely to several generic conventions, but Perez and Levin give each predictable development a sufficient tweak to make it seem both unexpected and hilarious. Although mercifully ditching the Cormanesque antics in which he had indulged in Monster Island (2004) and Mega Shark vs Giant Octopus (2009), Perez perhaps overdoes the monochrome flashbacks to the incident that scarred Corrigan for life and allows Lucy Davis to overdo the ditzy mannerisms that made her so adorable as Dawn in The Office. But, otherwise, he judges the tonal shifts well and coaxes relishable caricatures out of the willing supporting cast.

Forced to remain dour and tentative throughout, the dependable Corrigan gets little chance to shine. But he proves an effective foil for the effervescent Gade, who (like Elizabeth Olsen in Liberal Arts) impresses in spite of not quite being able to disguise the fact she is three years too old for the role. However, the stars here are Bostwick and Black, whose delivery of lines that would not have been out of place in Twin Peaks is nigh on perfect.

Finally, this week, comes a gem of a documentary, Diana Vreeland: The Eye Has to Travel, which was directed by Lisa Immordino Vreeland in collaboration with Bent-Jorgen Perlmutt and Frédéric Tcheng. Both a homage to the grandmother-in-law she never met and a celebration of the spirit of the times she captured with such panache during her stints at Harper's Bazaar and Vogue, this is a whistlestop tour through 20th-century taste that includes talking-head contributions from the models, photographers and designers who owed their fame to Diana Vreeland and recall with enormous affection being simultaneously inspired and intimidated by her as she transformed the manner in which magazines were edited and read and the way in which fashion was perceived by the masses.

In 1983, the 80 year-old Vreeland hired George Plimpton to ghost write her memoir, DV, and extracts from the transcript of their conversations in the living room she called `a garden in hell' are voiced here by Annette Miller and Jonathan Epstein to link the dazzling array of archive clips, glossy print spreads and interview testimonies that not only bring Vreeland alive, but also the compellingly contrasting eras through which she lived. Occasionally, Miller sounds more like Katharine Hepburn than Diana Vreeland. But this is an innovative method of structuring the wealth of material and making it both educational and entertaining.

Diana was born in Paris in 1903 to ex-pat British stockbroker Frederick Dalziel and his big-game hunting American wife Emily, who made no attempt to disguise the fact that she thought her ugly and gauche in comparison to her younger sister, Alexandra. Yet Diana seemed to have a blissful childhood, whether she was witnessing the Coronation of George V or being taught to ride in the Rocky Mountains by Buffalo Bill. One quickly comes to realise that Vreeland had a blasé attitude to the truth, as the essence of an anecdote or recollection was always more important to her than any cold, hard fact. But it's almost an irrelevance whether she could speak any English by the time she arrived in New York at the age of 10. What matters is that she had a zest for life and a respect for creativity and freedom that came from watching the Ballets Russes in Belle Epoque Paris and Josephine Baker in Jazz Age Harlem.

Having earned a reputation for being a bit `fast' with the boys, Diana met and married Yale graduate Reed Vreeland in 1924 and relocated to London, where she began to move in couture circles and both befriended Coco Chanel and opened a lingerie store that supposedly furnished Wallis Simpson with the three nightgowns that nearly brought down the British monarchy. However, sons Tim and Frecky were primarily raised in Brewster, New York, where she insists she saw Charles Lindbergh at the start of his pioneering solo flight across the Atlantic, even though The Spirit of St Louis took an entirely different route.

Vreeland's own life was about to change direction, however, as while she adored being a wife, she found motherhood tiresome and the need to occupy her time and make a little pin money led to her being hired by legendary Harper's Bazaar editor Carmel Snow in 1937 to write the `Why Don't You...' column, which offered readers suggestions such as painting world maps on nursery walls to prevent children from growing up with parochial attitudes. She dropped the item on the outbreak of the Second World War, as she thought it inappropriate for such grave times. Yet, Vreeland could never understand the conflict, as, having once seen Hitler at the Munich Opera House, she was bemused why such a great nation would slavishly follow the whims of a man with such a ridiculous moustache.

Newly installed as Harper's fashion editor, Vreeland began to exploit the knowledge and chic acquired during her time in Europe and soon developed a keen eye for a ravishing layout and a striking model, as she discovered a young Lauren Bacall and started offering readers the chance to dream of alternative lifestyles rather than simply keep abreast of the latest trends. She published the first American pictures of the bikini and helped popularise blue jeans and photographer Richard Avedon and then-model Anjelica Huston eagerly credit her with devising the exotic location shoot and taking the magazine focus away from aspirations of perfect wifehood to fantasies of glamour and style.

But Vreeland also came to be known as a hard task mistress and former assistant Ali McGraw's memories of her terrorising underlings is amusingly contrasted with clips from Stanley Donen's Funny Face (1957) and William Klein's Who Are You, Polly Magoo? (1966), in which Kay Thompson's Maggie Prescott and Grayson Hall's Miss Maxwell were thinly disguised parodies of a maven who became such a byword for refinement that Jackie Kennedy consulted her over her outfit for John F. Kennedy's inauguration as president in 1961.

Yet, even though Vreeland wielded such power and influence, she could only command an annual salary of $18,000, Thus, when the publishers offered her a meagre $1000 raise, she accepted Alexander Liberman's offer to become editor of Vogue in 1962 and, once again, found herself helping to define the zeitgeist as she introduced American readers to The Beatles and The Rolling Stones, as well as the new breed of supermodels typified by Jean Shrimpton and Twiggy. Recognising in the Swinging Sixties the same social exuberance and cultural audacity that had characterised the Roaring Twenties of her own youth, Vreeland not only understood what she termed the `youth quake', but also appreciated that air travel was shrinking the planet and she began championing the introduction of ethnic styles into mainstream fashion and sent photographers like David Bailey and Joel Schumacher to the far-flung corners to create the most eye-catching spreads.

She also encouraged her shutterbugs to emphasise what others might have considered the imperfections of their subjects and made a virtue of such features as Barbra Streisand's Nefertiti-like nose. Thanks to Vreeland, stars like Elizabeth Taylor, Sophia Loren and Catherine Deneuve became mannequins, while such hip models as Penelope Tree, China Machado, Lauren Hutton, Veruschka von Lehndorff and Marisa Berensen (who was Vogue's first-ever nude) became celebrities. Even designers like Manolo Blahnik, Diane von Furstenberg and Calvin Klein acknowledge their debt, as Vreeland made fashion desirable, relevant and accessible to a new generation of women.

Readily embracing vulgarity, kitsch and even pornography, Vreeland fearlessly accepted the changes brought about by the Civil Rights movement, drug culture and the gay scene (although she always questioned the validity of feminism). Consequently, Vogue always felt ahead of the game, as she experimented with imagery, fonts, colour and white space to ensure the eye always travelled across features that she helped shape with memos fired off during her dressing-gown mornings and hectic office afternoons before she swanned off in the evening to the latest soirée, premiere or opening. Undaunted by the death of her husband in 1966, she found herself at the centre of a new clique that included such Hollywood icons as Warren Beatty and Jack Nicholson. However, not everyone was seduced by the Vreeland pizzazz and, following a series of complaints from advertisers, she was fired from Vogue in 1971 and never forgave Liberman for lacking the courage to break the news in person.

Momentarily, Vreeland was cast adrift. But before she could entertain any feelings of self-doubt, she was invited to become a consultant to the Costume Institute at the Metropolitan Museum of Art, where she soon began ruffling feathers as she played fast and loose with historical accuracy to curate exhibitions that enticed unprecedented crowds to learn more about 18th-century France, Sergei Diaghilev, the fashions of her own salad days and the allure of Golden Age Hollywood, as well as the work of such contemporary designers as Yves Saint Laurent. Her flamboyant approach and penchant for celebrity parties irked stuffier colleagues like Philippe de Montebello, who received a flea in his ear when he attempted to question her academic credentials. But, if Vreeland occasionally followed fancy rather than fact, she brought a new freshness to the displaying of vintage clothing and revealed how fashion reflected the personality of a period and its people.

The trio of directors cannot be faulted for the glittering galaxy assembled to offer their insights into Diana Vreeland's life and work. In addition to sons Tim and Frecky, there are also contributions by her grandsons Alexander and Nicky and great granddaughter Olivia, as well as by onetime assistants Felicity Clark, Simon Doonan, Harold Koda, Katell le Bourhis, Tonne Goodman, Jeff Daly, June Burns Bove and Kurt Thometz (who was her personal librarian), writers Ingrid Sischy, Bob Colacello, John Richardson and Reinaldo Herrera, editors Barbara Slifka, Rae Crespin, John Fairchild, Polly Devlin, Susan Train, photographers Lillian Bassman, Melvin Skokolsky and Stephen Paley and designers Hubert de Givenchy, Oscar de la Renta, Anna Sui, Tai and Rosita Missoni, Kenneth Jay Lane, Carolina Herrera and Pierre Bergé.

Some are only accorded single lines. But each conveys the awe and allegiance that Vreeland expected from her associates, along with their appreciation of her achievement. Yet this is never a hagiography, with the closing animation depicting her caricature sitting behind Lindbergh at the start of his epic flight and suggesting that Vreeland recognised that she was part of the illusion she had contrived and that it was her duty to play up to her own imperious myth.