High frame rates aren't completely new to audiences. Digital TV broadcasts in the U.S. have been transmitted at higher frame rates for years, said Peter Lude, president of the standards-setting body, the Society of Motion Picture and Television Engineers. TV images look very clear because they're refreshed 60 times per second, even though only half the image hits the screen each time.
By contrast, movies shot at 24 frames per second are blurrier. That's because movie cameras' shutters are open longer at slower frame rates. As people or cars in a scene move, more of that motion is captured in a single frame, resulting in blur. Many people describe this as a "film look" that is "soft" or "cinematic."
It also means that some details remain too blurry to be seen, helping hide imperfections and making life in the movies appear somehow better than reality.
The traditional frame rate also leaves in some so-called "artifacts" that most people nowadays subconsciously accept as part of the movie experience, Lude said. Credits can seem to roll up the screen in dozens of little hops, and quick pans of a restaurant can seem staggered. It's one reason why filmmakers focus on passing waiters in such shots, so we're not distracted by these flaws, he said.
"What (Jackson) did was eliminate an artifact that has been present in all movies since the 1920s," Lude said. "Now it looks more real. Some people say, 'I don't want it to look more real.'"
Jackson compensated for some of the increased clarity by purposely leaving the shutter open longer than normal, adding back some of the lost blur. Still, the images are sharper than before.
Jackson has said on his Facebook page that this adjustment gives his high frame rate version a "lovely silky look" while also making the traditional 24 frames per second version "very pleasing."
At a press tour in New York on Thursday, Jackson said it will be up to audiences to decide.
"As an industry, we shouldn't really assume that we achieved technical perfection with motion pictures back in 1927," he said. "There are ways to make the theatrical experience more spectacular, more immersive and that's what we're trying to do."
Time Warner Inc.'s Warner Bros., which is distributing the movie, is being conservative with the new format, careful not to bet too heavily that audiences will love it.
The studio is releasing higher-frame versions only in 3-D, not 2-D, partly because the perceived benefits are better in 3-D. And it's limiting such screenings to about 450 locations in North America, a little over 10 percent of the footprint of most major wide release movies. About 1,000 screens in the world will show "The Hobbit" in higher-frame 3-D. That's far fewer than the tens of thousands of screens that projector makers Barco Inc. and Christie say are currently capable of showing the format worldwide.
"Nobody wants anyone to feel like this is something being shoved down their throats," said Carolyn Blackwood, an executive producer on the movie and executive vice president of the Warner Bros. division New Line Cinema. "People don't always embrace change."
She said the studio's strategy is to give fans a choice.
"If people are interested and want to see what we're talking about, they'll seek it out and they'll find it and it'll be available," she said. "If they're filmic kind of people, they can go and see it in standard 24 frames per second and be happy."
U.S. theater owners aren't charging extra for it, saying they want to give people a chance to experience something new for free.
"We believe this will deliver great value to our guests," said Ken Thewes, chief marketing officer for Regal Entertainment Group, the largest theater owner in the U.S.
And despite the increased clarity, 48 frames per second is not the limit. Cameron has said he's considering shooting the sequels to "Avatar" at a rate as high as 60 frames per second.