Oscar-winning director Steven Soderbergh on Thursday beat back criticism that his four-hour epic on the life and times of Ernesto "Che" Guevara broke too many tried and tested conventions.

At four hours 28 minutes, filmed entirely in Spanish, and shot documentary-style, Soderbergh had barely premiered 'Che' at Cannes when the pundits unleashed a barrage.

Who did Soderbergh make the film for, one critic asked on Thursday. With its entirely Spanish-language cast from across Latin America, how was he planning on selling it to multiplexes in subtitle-allergic North America?

"I can only make something I want to see," the US director fired back. "You can't make a film on Che Guevara that has credibility unless it's in Spanish."

"I'm hoping that brand of cultural imperialism is over, that we can now shoot in local languages," said Soderbergh, two years after Alejandro Inarritu's 'Babel' broke new barriers by offering sequences in several languages from several parts of the world.

As to the length, retorted the director of the 'Ocean's' movies, "if you're going to have context you have to have size."

Brutal about the length

But trade mag Variety was brutal about the length: "It would be surprising if this Cannes version, which was reportedly rushed to completion to meet its playdate, even sees the light of day again," it wrote.

"By any normal standards, retailoring, presumably down to manageable length as a single film, is called for to allow 'Che' any significant public life."

Competing for the festival's top Palme d'Or prize, the $60-million movie has been the most talked-about title for sale at the festival, the world's briskest industry marketplace. Soderbergh made his name at Cannes, winning the Palme at 26 with 'Sex, Lies and Videotape'.

But the Che movie almost died in the bud when US backers failed to invest, and US distribution rights still remain to be sold.

Soderbergh initially signed up to produce, but not direct, the film — almost a decade in the making — on the rise and fall of the revolutionary hero while shooting in 1999 his Oscar-prized 'Traffic' with current 'Che' star Benicio Del Toro.

Bad guy image

Puerto-Rican born Del Toro recounted how like the average American he grew up with a bad guy image of Cuba's hero until stumbling on a book on the guerrilla leader in Mexico. "He had a really warm smile. I bought the book and then read more. The love people had for this man made me more interested."

Del Toro, Soderbergh and co-producer Laura Bickford drummed up European funds, for what was first supposed to be a two-hour movie based in Bolivia on Guevara's botched attempt to export the Cuban revolution to the rest of Latin America.

But when the director originally signed up also quit, Soderbergh decided to take the helm while adding more footage. Now Part 1 of the movie, it chronicles the overthrow of Cuban dictator Batista by Guevara and Fidel Castro.

"We made the film backwards, starting with the second part, then adding the first," he said.

How the marathon movie will be screened in theatres remains a mystery, with Soderbergh saying his favourite scenario would be for each cinema to initially offer the two films together, then one at a time.

His decision to go for a meticulous recreation of the real-life drama of the Che, with the help of a new high-performance digital RED camera, also drew the critics' knives.

"Why no movie-moments, love interest, emotion?" Soderbergh was asked.

"It's ridiculous that people are upset by something that's not conventional," he replied.

"We're trying to give a sense of what it was like living around this character," said Soderbergh. "He had a life that was loaded. He accomplished in 10 years what could take people hundreds of years."