Ethan Hawke has talked about his long-running collaboration with director Richard Linklater.
The star is reuniting with the Before Midnight film-maker again on a film called Boyhood, which began in 2002 and runs for 12 years.
"We're doing a movie called The 12 Year Project. We've been making a short film every year for 12 years. It is about a young boy growing up, it takes him from six to 18," the actor said.
The film, which stars Ethan and Patricia Arquette as a divorced couple with Ellar Salmon as their son, follows the family over the years and looks at how their relationship with each other changes in that period.
Richard added: "We actually started that before we did the second one of these (Before Sunset) so I think the idea of a long-term project that has to do with time came out of that."
The film-maker has previously said: "I've long wanted to tell the story of a parent-child relationship that follows a boy from the first through to the 12th grade and ends with him going off to college.
"But the dilemma is that kids change so much that it is impossible to cover that much ground. And I am totally ready to adapt the story to whatever he is going through."