The August bank holiday weekend has always been an tricky time for cinema releases. With the schools due back in a matter of days, there is little point in launching an SFX-laden blockbuster or a specifically kid-friendly picture, as there simply won't be the daytime audiences to keep the box-office tills ringing. That said, the weather is usually so dreadful that people look to the local multiplex to provide one last treat before young and old alike clamber back into the old routine.

This has already been an odd summer for movies, with minor distributors being forced to fight shy of the Olympics as well as the latest Hollywood behemoths. But it seems strange that these companies packed so many titles into the first third of the August schedule when there was clearly so little mainstream fare on offer in the last fortnight and now have nothing left when the competition is less daunting.

Twentieth Century-Fox has been pushing Ben Stiller's suburban comedy The Watch (even at the expense of its own Farrelly brothers slapstick biopic The Three Stooges), but it is doubtful whether it will do as well as Lionsgate's Keith Lemon: The Film, which has been primed to become this year's The Inbetweeners Movie - ie a cheap and cheerful TV knock-off with a built-in fan base and a decent curiosity factor.

Up against these crowd-pleasers is James Marsh's adaptation of ITV newsman Tom Bradby's novel, The Imposter, which stars Clive Owen and Andrea Riseborough in the story of an IRA activist who turns informer for MI5; Bart Layton's The Imposter, a fact-based thriller about the disappearance of a 13 year-old boy from San Antonio Texas in 1993; Bela Bhansali Sehgal's Bollywood romcom Shirin Farhad Ki Toh Nikal Padi; and Tim Heidecker and Eric Wareheim's absurdist comedy, Tim and Eric's Billion Dollar Movie, which is playing in one London venue to give the DVD sales a boost.

The arthouse selection, therefore, is limited to three pictures this week. The pick is easily the revival of Orson Welles's teasing documentary F For Fake (1973), but there is also much to admire in Maryam Keshavarz's Circumstance and enjoy in Jiang Wen's Let the Bullets Fly. However, it might have made more sense to spread the August alternative options a bit more evenly across the month.

Despite lapsing into soap operatics and creating a clumsily exaggerated fundamentalist caricature, Maryam Keshavarz does a decent job of capturing the mood of rebellion among young Muslim women in Circumstance. Rooted in fact, this laudable lesbian love story ventures into the little seen underworld of Iranian youth culture with its eyes wide open. But Keshavarz is more intent on busting taboos than practicing dramatic restraint and, thus, while this is bound to provoke, it is never as effective as it might have been had the more gratuitous excesses been reined in.

At their Tehran high school, Nikohl Boosheri and Sarah Kazemy seem like any other 16 year-old girls. But they come from very different sides of the tracks, with the orphaned Kazemy living her uncle Fariborz Daftari Daftari and grandmother Siro Fazlian and Boosheri being taught the delights of fine wine, Bach and nostalgic Persian folk songs by middle-class liberal business Soheil Parsa and his nurturing surgeon wife Nasin Pakkho.

Kazemy's parents were noted critics of the Islamic Republic and she shares their rebellious spirit. She takes Boosheri to covert video stores renting forbidden American movies and secret parties in warehouses and luxury apartments. Moreover, when they go on a trip to the seaside, she coaxes her into defying convention by stripping down to her underwear to go for a swim as dawn breaks. It's almost inevitable, therefore, that their friendship should blossom into romance and they begin fantasising about being able to live and love freely in Dubai.

Everything changes, however, when Boosheri's musician brother, Reza Sixo Safai, comes home unexpectedly from rehab, where he has been treated for crack addiction. Despite still smoking hash, he has become a fervent Muslim and his disapproval of his parents' politics and his sister's social activities prompt him to enrol in the state morality police and place surveillance cameras in every room of the house so he can keep tabs on the perfidious infidelty under his roof. Moreover, he begins to take a fancy to Kazemy and his determination to possess her brings matters to a traumatic head.

Whether depicting Boosheri and Kazemy surrendering themselves to animalistic rhythms or cavorting around in lingerie and high heels, Keshavarz seems determined to assert the right of Iranian women to do as they please regardless of religious authoritarianism or patriarchal tyranny. Indeed, she even suggests that so oppressive have things become under the Ahmadinejad regime since the crushing of the Green Wave that self-indulgent pleasure-seeking has itself become a form of political protest.

But her hard-hitting message is compromised by the waywardness of the plot, which becomes increasingly detached from reality as Safai's crazed reign of terror intensifies. The performances become casualties of this onslaught, which seems to pander to diasporic expectation, unlike the more subtle examinations of the gyno-experience inside contemporary Iran presented by such insiders as the Makhmalbaf clan, Jafar Panahi, Asghar Farhadi and Bahman Ghobadi, who first introduced audiences to the counterculture in No One Knows About Persian Cats (2009).

Shooting in 16mm, Brian Rigney Hubbard makes the most of locations in Lebanon and Dubai, while a score by Ravi Shankar's great-niece Gingger adds a touch of exoticism. But, despite the best efforts of Boosheri and Kazemy (who vivaciously convey the intoxication of first love), this is never as deep, defiant, daring or dangerous as Keshavarz clearly intends.

Jiang Wen started out as an actor and featured in such landmarks in the emerging Chinese cinema tradition as Xie Jin's Hibiscus Town (1984), Zhang Yimou's Red Sorghum (1987) and Mabel Cheung's The Soong Sisters (1997). However, he turned director with In the Heat of the Sun (1994) and Devils on the Doorstep (2000), which respectively earned star Xia Yu the Best Actor prize at the Venice Film Festival and the Grand Prix at Cannes. But Jiang reached his biggest audience with Let the Bullets Fly, a record-breaking, all-action homage to the films of Sergio Leone that is so in thrall to the spaghetti Western that it could justifiably be called a noodle Eastern.

Some time in the lawless 1920s, known in China as the Warlord Era, Ge You and his wife Carina Lau are riding though a parched, hilly wilderness in a horse-drawn train with their factotum Feng Xiaogang. Ge has spent much of the time since the 1911 Wuchang Uprising exploiting the chaos across the country by arriving in remote settlements and claiming to be a representative of the new government. However, before he can present himself as the governor of Goose Town, his conveyance is attacked by bandit Jiang Wen and his sidekicks Zhang Mo, Liao Fan, Shao Bing, Wei  Xiao, Li Jing and John Do.

Defenceless after his bodyguards are killed in a gunfight, Ge claims that Feng is the dead governor and has no option but to allow Jiang to assume his bogus identity (and even supplant him as Lau's husband), while he adopts the role of counsellor. All seems to be going smoothly as they are welcomed at the gates by Zhou Yun and her drummer band. But local bigwig Chow Yun-fat deeply resents the intrusion of officials into his fiefdom and he starts to plot their demise with sidekicks Chen Kun and Yao Lu as he spies on the newcomers from his citadel as they parade along the main street.

Ignoring Ge's suggestion that they ally with Chow to fleece the poor, Jiang tries to rein in the mobster and charges one of his underlings, Jiang Wu with assault. However, Chow gets his revenge by framing Mo (who is Jiang's godson) for theft in a tea shop and the youth performs ritual suicide to expose the contents of his stomach and prove his innocence. Cautioning Jiang against a violent reprisal, Ge suggests they accept Chow's dinner invitation, where they quickly realise he has no idea about their deception and Jiang willingly agrees to join an expedition to hunt down his outlaw self.

Despite the bonhomie, Chow sends assassins to kill his guests during the night. But only Lau falls victim to the attack and Ge confesses his true identity in his grief. Undeterred, Jiang sends his accomplices to kidnap Chow and members of Goose Town's leading families. However, they succeed only in abducting Chow's body double and Jiang refuses to accept the ransom money when the ordinary townsfolk are browbeaten into donating it. Moreover, he agrees to provide sanctuary to Zhou (who has defected from Chow's camp) and presents Miao Pu with a pair of fabulous jewels when she arrives to claim that Ge fathered her son when he was pulling his scam in Shanxi.

Chow hopes that capturing and killing the notorious brigand (ie Jiang) will reinforce his control over the town and he hires Hu Jun to impersonate Jiang in the hope that he can trick him into blowing his cover. He also orders Chen to plant a gigantic landmine on the main road so that he can increase his chances of destroying his nemesis. His plan partially works, as Shao is killed in skirmish with Chow's forces, while Ge drives over the mine in his carriage in despair after discovering that Hu has killed Miao and his son.

Vowing revenge, Jiang returns to Goose Town and kills Chow's doppelgänger in front of the residents, who seize the weapons he has offered them to storm the citadel. Shruggingly conceding defeat, as his belongings are looted by the liberated locals, Chow accepts Jiang's offer to commit gentlemanly suicide. But, when he tries to slip away unnoticed, Jiang has him killed by Jiang Wu (who is actually Jiang's off-screen brother). Liao announces that he plans to marry Zhou (who is Jiang's real-life wife) and start a new life in Shanghai and Jiang rides after them, as he finds the prospect of new adventures more enticing than ruling over a backwater that no longer need his Robin Hood-like assistance.

As can readily be ascertained from the above, this is a gleefully intricate tale that is made all the more difficult to follow by its plethora of impersonations, duplications and convolutions. However, Jiang Jiang triumphs both as the director and the star of this rollicking yarn that not only recalls the spaghetti classics of the 1960s, but also Zhang Yimou's lavish period pieces and South Korean Kim Jee-woon's The Good, the Bad and the Weird (2008). Jiang is ably assited by Ge Lou and Chow Yun-fat, who invest their buffoonery and dastardliness with plenty of pantomimic brio. But the remaining members of the bullish cast combine muscularity with athleticism in the numerous set-pieces choreographed by Ailen Sit.

Some of the countless CGI effects are a touch sub-par, but they add to the mood of mischief that pervades this latest reworking of Akira Kurosawa's 1961 masterpiece, Yojimbo. Moreover, Jiang doesn't entirely rely on post-production trickery, as he keeps Zhao Fei's camera forever on the move to match the twists and turns of a storyline that is greatly enhanced by Wong Kar-lang, Gao Yiguang and Yu Qinghua's production design, William Chang's costumes and a score by Joe Hisaishi and Shu Nan that sustains the sense of playful epic.

Working from a novel by Sichuan author Ma Shitu, Jiang and his numerous fellow scribes may have allowed the action to sprawl in places, while they certainly over-complicate the denouement. But they also occasionally pause proceedings for some acerbic observations on the misuse of power, the corruption of minor officials, the impossibility of ruling a vast country and the role of injustice and violence in maintaining control, although any allegorical allusions are safely buried beneath the slick surface of a breakneck romp that completes an accidental trilogy of Western pastiches that also includes Zhang Yimou's A Woman, a Gun and a Noodle Shop (2009) and Li Weiran's Welcome to Shama Town (2011).

Fittingly, deception is also the theme of F For Fake, the last film of any significance completed by that wayward genius Orson Welles. As much a dissertation on authorship, audacity and authenticity as a conventional documentary, this cinematic sleight of hand centres on the career of professional art forger Elmyr de Hory. However, Welles was working on his unfinished opus The Other Side of the Wind when he was gifted several reels of footage by the French director François Reichenbach, who had recorded the interview between De Hory and the American writer Clifford Irving that formed the basis of the latter's 1969 book, Fake!

Initially, Welles planned to edit this material into a documentary for the BBC. But the breaking revelation that Irving's acclaimed biography of the reclusive tycoon Howard Hughes had been based on bogus documentation transformed the nature of the assignment and Welles persuaded Reichenbach to act as his cinematographer as he shot new scenes that would not only allow him to ruminate on the scams of Irving and De Hory, but also to perpetuate a ruse of his own in a coda about companion Oja Kodar and Pablo Picasso that provided a mendacious counterpoint to the truth that Welles insisted he had been peddling in the first hour.

An first glance, this all seems a bit far-fetched and pretentious. But such was Welles's mastery of his medium and his talent for spinning a yarn that his prestidigitatious essay is an endless delight that provokes and amuses in equal measure and leaves one lamenting (as, indeed, every Welles film does) that he had managed to realise just a few more of the many pictures he had either planned, started or been forced to abandon through lack of funds.

In the opening scene, Welles beguiles two boys in a railway station by performing a magic trick that seems to turn a key into a coin. But alert viewers will realise that they are about to become the guileless onlookers. Georges Méliès, a magician who pioneered trick cinematography at the end of the 19th century, ended his life running a sweet and toy kiosk on the station at Montparnasse and Welles recognised Méliès's ability to manipulate imagery and create illusions through editing. Thus, he shows himself at several junctures throughout the film seated at an editing desk and challenges the audience to guess whether he is splicing together threads of truth or weaving indistinguishable deceptions.

Before he was jailed by the Spanish authorities, the Hungarian painter Elmyr de Hory had made a comfortable living on the island of Ibiza by creating undiscovered originals by such renowned artists as Matisse, Modigliani and Renoir and fooling international experts by appending signatures that withstood the closest scrutiny. Ending a year-long exile from his home, De Hory agreed to be profiled by Clifford Irving and Welles (who had a profound mistrust of biographers and their so-called art) used François Reichenbach's record of their meeting to speculate about the nature of fact and the extent to which a biography is a work of collusion that shows both subject and author in the best light.

However, Irving's exposure as a rogue forced Welles to rethink his approach. But instead of judging a struggling journeyman (whose scam was later filmed as The Hoax by Lasse Hallström in 2006, with Richard Gere as Irving), Welles decided to admit to a few fabrications of his own. Yet, in confessing how his twentysomething self had blagged his way into Dublin's celebrated Gate Theatre company by posing as an established American star, Welles also pulls the wool over the audience's eyes by inserting fictitious scenes into his reminiscence about the 1938 War of the Worlds radio broadcast that had convinced listeners across the country that they were being invaded by Martians. Moreover, he compounds the lie by convincing us that his Croatian paramour Oja Kodar had once posed nude for Picasso and then sold copies produced by her father of the resulting pictures while she kept the originals for herself.

One should know from the entreating expression on Welles's face that he is leading us astray and using all manner of jump cuts, zooms, whip pans, double exposures and freeze frames to disguise his legerdemain. But this is the man who cut clips from Ernest B. Schoedsack's The Son of Kong (1933) into his feature debut, Citizen Kane (1941), which opens with a near-perfect replica of a March of Time newsreel. He is the same auteur who, in warning an interviewer that if they kept on prying he would resort to fibs, conceded that 75% of everything he said in interviews was entirely made up.

The release of a magnificent Criterion DVD edition has made F For Fake in isolation seem like only part of the story. Yet, even without the wealth of extras including the droll nine-minute trailer that Welles fashioned with Kodar and cinematographer Gary Graver, this remains a tantalising watch, whose influence on post-modernist editing techniques remains undimmed. But what makes this so pleasurable is the opportunity it affords audiences to spend some time with Orson Welles some three decades after his death. Perhaps motion pictures are the ultimate artform after all, as they enable mere mortals to cheat death.