Kevin Costner won't judge the success of 'Horizon' on box office figures.

The 69-year-old star has self-financed the epic Western saga – in which he both directs and acts in – but isn't disheartened by 'Horizon: An American Saga – Chapter 1' failing to make an impact in its opening weekend in cinemas as long as his four-film vision is realised.

Kevin told Entertainment Weekly: "I've lived with movies and what happens to them on their opening weekend. If we put so much pressure on that, we're bound to be disappointed."

The 'Robin Hood: Prince of Thieves' actor added: "I'm really happy that 'Horizon' looks like what it's supposed to look like, and that's the way it'll look the rest of its life. And that's really important to me in this process.

"Would I love that it would be highly, highly successful? Of course, I'd like that. My ego would like that; everyone would like that. But I am happiest that the movie that you and I are talking about looks the way I want it to look."

The second 'Horizon' film will be released in August and Costner was determined to get both pictures released in the cinema.

He told IndieWire: "That's where I belong.

"And I also felt that I have to look at things from a monetary standpoint, because I have so much invested, that I didn't want to throw that window away. But artistically, I thought it should be on the big screen."

Despite the initial box office disappointment, Kevin is pushing on with his plans to make a quartet of movies.

He said: "People are going to just keep coming, and the story is going to keep coming, and it's going to expand."