He also denied suggestions that the film, which hits U.S. and British theatres on April 6, was a way of cashing in on the tragedy, which happened on April 15, 1912 with the loss of more than 1,500 lives.

"I just think it makes it more immersive," Cameron said of the 3D re-make. "It kind of turns up the experience to 11 instead of 10," he told reporters late on Tuesday at the red carpet world premiere held at London's Royal Albert Hall.

Titanic, starring Kate Winslet and Leonardo DiCaprio, earned more than $1.8 billion at the global box office.

Before inflation is taken into account, it is second only to Cameron's 3D sci-fi adventure "Avatar", which grossed $2.8 billion, in the all-time ticket sale rankings.

Cameron, who has just returned from a solo dive to the deepest point in the ocean, defended his decision to re-release Titanic in 3D format.

"Look, there's always going to be people that can piss in the soup of anything good," he told reporters, when asked if he was capitalizing on the Titanic tragedy and its upcoming anniversary.

"But frankly I think that remembering Titanic, remembering the history -- that's what the film was there for. That's why I made it, you know.

"I was fascinated by the story, I was fascinated by the history, the people that were heroic, the people that lost their lives. I was genuinely touched by the tragedy when I was there at the wreck.

"I think the film is a good focusing agent for that at this time when we should be remembering the wreck and its message, the disaster and its message for all of us."

For British actress Winslet, who shot to fame after appearing in the original, the 3D experience was a strange one.

"It's weird," she told Reuters. "I mean, it is like being forced to go through a photo album of your former self for three and a half hours solidly. It's quite strange you know."

Asked how she felt about watching herself on screen in 3D during the film's more intimate moments, she replied:

"Oh terrible! Wouldn't you? I am not going to look. I'll be in the bar by that point I expect -- or on the floor!"

DiCaprio did not attend the premiere as he was shooting new movie "Django Unchained", directed by Quentin Tarantino, in the United States.

(Writing by Mike Collett-White)

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