Felicity Jones is in great demand for films but says she has no plans to abandon the West End.
Jones, 27, landed the role of Luise Miller at the Donmar Warehouse having already scooped the special jury prize at this year's Sundance Film Festival for Like Crazy, Drake Doremus's low-budget movie.
Jones will work on movie projects in New York when her Donmar run ends. A second film with Doremus is also in the pipeline.
But she says more lucrative film work cannot take her away from the theatre. "I absolutely want to keep a balance," she said after Luise Miller opened last night. "I love working with Michael Grandage and once you find you have a really good working relationship with someone, it is vital you continue that.
"It is such an extraordinary challenge that I wouldn't ever be able to leave it. It tests you in a completely different way as an actor that you don't find in films. Why would you ever not want to do both?"
Jones, who lives in east London, said of the Luise Miller cast: "We have put a lot of heart and soul into this play and it has been absolutely brilliant that people liked it as much as they did.
"It is a fine balance between humour and tragedy... we work very hard to maintain the tragedy in the lighter moments."