An unassuming hairdressing salon in a shopping precinct in Lincoln is an unlikely venue for the world premiere of a film directed by a globally famous actor. But behind a velvet rope, between the washbasins, that is exactly what is happening in Sincil Salon in Sincil Street in Lincoln town centre. The film is called Medusa’s Ankles, and the director is Bonnie Wright – better known to tens of millions as Ginny Weasley in the Harry Potter film series.

The venue, in fact, is wholly appropriate: Medusa’s Ankles, adapted from a short story by AS Byatt, is set entirely in a hairdresser’s. It stars Kerry Fox as a woman disconcerted by the signs of ageing – particularly her greying hair, which she is determined to keep “natural” – and Jason Isaacs as a charismatic, bullying hairdresser with whom she has a fraught, fractious relationship. The 20-minute film is showing over three days in the salon, which will be open for normal hairdressing operation throughout.

“What’s so great about this,” says Wright, “is that we spend so much time experiencing things on the internet and social media that an actual physical film screening is rare.” Wright also says she likes the “exhibition-y” feel of the event, which appears as much a gallery installation as a cinema premiere. The screening has been organised by Lincoln-based Mansions of the Future, a three-year cultural project designed to “allow the public to collaborate directly with artists”; future events include a new production with nonprofessional actors of Steven Berkoff’s 2001 play Ritual in Blood, about the medieval “blood libel” surrounding Little Saint Hugh of Lincoln. Wright very much approves of Mansions of the Future’s aim to bring culture to the people: “I was very lucky to have grown up in London and had that access to the arts. The way I got into this was through culture and education, and it’s so important to take it outside of the capital city.”

Wright, 27, bears little resemblance to the pale-faced schoolgirl we last saw settling down to raise a family with Harry Potter (after helping to see off Voldemort’s army at the climactic Battle of Hogwarts). Since finishing the series eight years ago in 2010, she has opted to develop a career largely behind the camera, directing short films, shooting music videos and art projects and recently branching out into commercials. Unlike her fellow Potter alumni, Wright has taken only a few acting jobs since, opting instead to study film-making at the London College of Communication and setting up her own production company in 2012.

Medusa’s Ankles has an unlikely subject for a film-maker in her late 20s: a woman experiencing a menopausal midlife crisis. “It’s something I am obviously yet to experience!” she says. “But I think I and a lot of people can understand it: we’ve all sat in a hair salon and been at the mercy of someone else’s opinion. Sometimes you go in knowing exactly what you want, other times it’s about what they think you should have. The story – and the film – is about that sensory interaction, that heightened space between the hairdresser and their client.”

The film, she says, is also partly intended as a showcase for how she can handle larger sets and complex lighting setups (“It’s definitely strategic”), and she has her sights set on a full-length feature film. Wright is a committed activist for environmental causes, and is working on a script that, she says, is “heavily inspired by the work I’ve been doing with Greenpeace around ocean plastics, but with a mythological and science fiction twist”.

Wright is keen to show she has moved on from Potter, but acknowledges the debt she owes to the role she secured as a nine-year-old after her older brother Lewis suggested she go along to an open casting call. “At the beginning I was in complete awe of the whole thing,” she says. “All of us were pretty much learning about film-making and acting as it was happening. It was only as the films developed and the characters became more complex that it became more like a job. Looking back, what I loved about those films is that everyone, from the cinematographer to the set designer, were at the top of their field. To watch people for whom the craft of film-making was so important – that stayed with me.”

She also credits the Potter films for pushing her towards writing and directing: “Doing such big films gave me a desire to get more out of film-making, to get deeper into the process. When you are acting you are observing so much happening around you. I am directing actors having been directed myself, and there is specific type of language you have that is so unique. If you’ve been on the other side of it, it’s such a lovely experience.”

Wright has not been shy about putting her industry contacts to good use. Her graduation film, a 10-minute drama about a small girl who befriends a bereaved older man, featured David Thewlis, who played Remus Lupin in the Potter films; and the star of her second film, a poetic piece about a young man dealing with the death of a lover, was Christian Coulson, who played the teenage Tom Riddle in Harry Potter and the Chamber of Secrets. Isaacs, in her new film, is another Potter regular, having played Lucius Malfoy in six of the films.

“For sure, I have an advantage in terms of the access to these people,” she says, “as well as to the experiences I’ve had along the way. But respecting that is really important. If you are going to call upon actors or connections, it’s important not to utilise them when they are not needed. Only if the actor would be right for the role, rather than choosing them for the sake of it.”

• Medusa’s Ankles is at the Sincil Salon, Lincoln, until 26 May