Getting people to open their wallets for a first feature is never easy, says actor-turned film-maker David Leon, whose provocative debut, Orthodox, is playing in the UK Jewish Film Festival. "You know no one is going to give you that opportunity on a silver plate. So you have to find innovative ways of working around the system".

He started by making a short version, as "a kind of pilot", to give potential investors an idea of what the feature-length movie would look and feel like. It worked. Orthodox stars Stephen Graham as an Orthodox Jew called Benjamin who has alienated himself from his community by becoming a boxer. The film's Orthodox Jewish backdrop could be regarded as somewhat niche, but Leon always saw this as a strength.

"It was my intention that it would be niche," he says. "I think when you make a micro-budget film like this, you have a responsibility to deal with subject matter that is niche, and probably in an unconventional way, because it is the only thing that allows your story to stand out quite often"

Leon was born in Newcastle and is Jewish on his father's side. His religious upbringing was "moderate", with neither parent forcing their different point of view on him. "As a consequence, it made me much more inquisitive," he says. "And as I grew older, I became more intrigued by the conflicts that presented. And there was conflict when my mother and father got together."

He describes himself as "half-Jewish", an identification which is "a very personal thing", he says. He knows that, to the Orthodox community he is in no sense Jewish, and this informed some of the feelings surrounding Benjamin's situation in the film. A proud and dedicated family man, he longs to be fully accepted by his community, but the choices he has made in his life - including marrying a secular woman who converted - and his inability to meet the standards of observance demanded of him, have landed him between worlds.

His troubles begin when he defies his father and takes up boxing, following a violent antisemitic attack. Leon witnessed such an assault on a Chasidic boy by "secular kids" in Stamford Hill. The fact that it happened in liberal, cosmopolitan London made it seem all the more "archaic and barbaric," he says.

"The boy was wearing his beliefs on his sleeve. We don't all dress in a way that projects that for the world to see, and that's a brave thing. I wondered whether [the attack] would make him more intent on his values, or whether it could make him question them."

Leon spent 18 months in Orthodox communities in Newcastle, Gateshead, and north London doing background research and says he learned that "the idea of one man inflicting pain upon another was frowned upon in the context of the Jewish faith."

He found this interesting. In the early 1900s, Jewish men used boxing as a way to escape from being part of an underclass, and to assimilate and confront antisemitism. The sport turned them into heroes. But times change and Benjamin's reaction has to be seen in the wider context of the challenges now facing a community whose cultural cohesion, Leon seems to be suggesting, is under threat from modernity.

"The intention was never to make an observation on the religion," he explains. "It was much more about the culture. And not just about Jewish culture but about 21st-century culture and the demands that are placed on people within the Orthodox Jewish community as a consequence."

The community is not monolithic but composed of individuals. And while they may all live under the same umbrella of shared beliefs, "some will believe in certain things more extremely than others," says Leon. "I think what that does - where we have access to information at the touch of a button - particularly to kids and those that have less strength of character, or those that are more inquisitive, is present a real conflict that I think that the Orthodox Jewish community has never had before."

Benjamin's predicament - inspired by someone Leon met - allows the film to reveal some of the different sides of the community, which is portrayed honestly, seemingly accurately, and without sentimentality. It offers people love and security, but can be tough on those who don't observe its practices.

"That was my experience," says Leon. "The community can be a very safe environment and somewhere people feel very close, and there was a real sense of people looking after one another. But it's fair to say the demands placed on the individual are very restrictive and unrelenting. And I think if you don't toe the line, you can be cast aside and ostracised."

Many do meet the demands, of course. For Leon, as a film-maker, however, "those who fall through the cracks and fall by the wayside" are more interesting. That said, he stresses that he came away from the process of making Orthodox having encountered a "beautiful feeling of being willing to forgive. There is an unremitting attitude towards forgiveness, and I think that is something that the Jewish faith, particularly, upholds."