Angelina Jolie found making 'By the Sea' with Brad Pitt ''very heavy''.

The 40-year-old star wrote and directed the drama, which she and her husband star in as a ''deeply unhappy'' couple and she admitted scenes where they argued made the set uncomfortable for everyone working on the film.

She said: ''I'd be directing myself and him in a scene where we're having a fight, and I'd be pulling out the parts [of him] that have an aggression toward me or when you're frustrated with each other--it was very heavy.

''We kept joking that all of the crew felt like they were living in a house where the parents were fighting and you don't know where to stand or where to look.''

Angelina described the project as an ''art film'' and not what fans can usually expect to see her in.

She told the Directors Guild of America (DGA): ''It's an art film, the kind of movie that I like to see but not something I'm usually cast in.''

The brunette beauty's previous directorial efforts, 'In the Land of Blood and Honey' and 'Unbroken' - a love story set against the backdrop of the Bosnian civil war and a biographical drama of a World War II prisoner of war respectively - have been more ''issue-driven'' than 'By the Sea', and she admits she doesn't think she'll be doing much other work like her newest film.

She said: ''We're proud of ourselves for being brave enough to try it.

''I think 'By the Sea' was the hardest film for me because it wasn't [issue-driven]. It's something I probably won't do very much of.''