Tamsin Egerton has said appearing fully naked on screen is on her list of no nos.
The 24-year-old St Trinian's actress plays porn star Fiona Richmond in Michael Winterbottom's new film The Look Of Love, about Soho porn baron Paul Raymond.
Tamsin told the Daily Mail: "I've had to put my foot down. Full-frontals I won't do. Sexual acts I won't do.
"There are things on a list and there are certain things in the script that I've spoken to Michael about."
Steve Coogan stars in the film as Raymond, Anna Friel plays his wronged wife Jean, a former show dancer, Imogen Poots plays his daughter Debbie and Tamsin plays vicar's daughter gone bad Fiona, who was a performer in his films and his clubs, as well as his mistress.
Tamsin knew the role would involve some nudity when she signed up to it.
She said: "Fiona did take her clothes off, and part of the performance has to reflect that. You're always going to be wary, but Michael was a gentleman."
The actress added: "For me, it was going from teenage actress to playing a grown-up role: my gateway to showing more serious work.
"I communicated with Fiona via email, asking lots of questions. She kept saying this happened or that didn't happen, and I had to explain that I was playing the essence of her and I wanted to get that right."