The French actress likes to pick roles which are far from her own personality and fully immerses herself into movie preparation.

She has changed her approach to work since becoming a mum to five-year-old Marcel and has stopped bringing her characters home with her, but they still affect her on set, which her little boy can detect during a visit.

"He hates coming on set, because he feels that there's something totally different," she told Britain's Daily Telegraph newspaper. "My hair is different, my look is different, but more than that, my energy is totally different."

She added her son "would freak out" if she bought part of a character home with her, so she no longer allows herself to become all-consumed by a part.

"Being a mother and an actress you have to find a different kind of balance in your life, because the projects I choose are very far from who I am," she explained. "I'm interested in exploring the unknown and I'm willing to go as deep as I can when I prepare and shoot a movie.

"Before being a mother, I had this period of time which was dedicated to the movie, the role and nothing else, like I was going into another world. Having a child changes things because I have to organise myself differently.

Marion, 41, is currently expected her second child with partner Guillame Canet and she told the publication she looking forward to seeing how a new person affects their family dynamic.

She is also considering cutting back on work because she has had an intense schedule with films such as Allied, Ismael's Ghosts and the upcoming Assassin's Creed.

"I love being an actress, but I might work less; certainly less than last year, when I worked a lot," she added.