The Truth About 6K Page 2


Both 2K and 4K are generally regarded as state-of-the-art for film transfers capturing virtually all the detail contained on 35mm film. Current high-definition media (1080p) has a top resolution of 2K, and many films are being transferred to digital storage at 4K. What exactly do these numbers mean?

2K places 2,048 pixels horizontally across the image, and 4K uses 4,098 pixels. The vertical resolution can vary according to the image being scanned. For example, a 4K scan of the entire 35-mm film frame would be 4,096 x 3,112, while a 4K image of a 1.85:1 output will be 4,096 x 2,214. The bottom line is that 2K has 13% more pixels than HD RGB, and for the same aspect ratio, 4K has four times the number of pixels as 2K. In other technicalities, such as bit depth and color format, 4K, 2K and HD RGB are the same (see How Many Ks Do I Need" at the Digital Cinema Society site for more information).

6K transfers up the ante; it places a whopping 6,144 pixels horizontally across the image, but it doesn't add any information that's not in the original film. Are you just adding better resolution of film grain?

Lowry also feels the lenses used to shoot A Star is Born will limit the effectiveness of a 6K transfer. A Star is Born was shot in CinemaScope, which only lasted about 10 years before being replaced by Panavision. Cukor supposedly hated CinemaScope (the lenses could distort images), and is known to have said it felt like he was shooting through a coffin. (To combat the effect, he shot the far sides of the film in shadows, to focus the action on the actors, since this is a character-driven film, not the typical epic drama that would showcase the wide-screen format.)

According to Lowry, the only benefit of a 6K transfer over 4K might be some slight bit of detail in the noise floor: 4K resolution is already getting lost in the film grain. It's Lowry's position that instead of higher resolution, we should clamor for higher dynamic range. "Instead of 10 bit, why not 16 bit?," he asks. "Wouldn't it be nice to have high dynamic range?" This will reveal more details in the shadows and the blacks, with higher frame rates for film. The advantages of 6K, if there are any, are so subtle that the economics outweigh the benefits. Perhaps it would be more beneficial to save the money spent on such a costly transfer - a 6K scan requires a new telecine scanner, such as the Northlight CCD - and instead direct Hollywood budgets to save more historic movies at 4K.

Harris, meanwhile, actually has used the Northlight 6K scanner - on the subtitles in Godfather II. "I like the image to be as perfect and as true to the original film as possible," he says. "So rather than digitally creating new subtitles, we went back to the original title rolls, and we scanned them in 6K and down-res'd to 4K. This gave us a slight advantage - a knife edge image. Everything else we did at 4K."

Warner Bros. hasn't responded to requests for interviews, so we cannot say why they've chosen this movie for the 6K treatment, or if they're going to down-res to 4K. But Harris is coming down on their side.

"A Star is Born is an important film to do - it's one of the great films," he says. "The performances are extraordinary, and it's something that needs to be preserved. Is there an advantage to scanning at 6K? Slightly. Is it a good idea? I think it's a great idea. There is nothing in A Star is Born that's going to be above 4K. There just isn't any 4K information in there. But you make sure you get every last drop you can. And that is the Warner ethic. Do I think they're doing it correctly? Absolutely. Would I do it that way? Yup!"

Lowry's not buying it. "If you recover absolutely everything on the film, no matter what the display technology is in 100 years, you've already captured everything," he insists.

Maybe Hollywood needs to start filming in higher fidelity so we'll actually need 6K display tech. How about shooting at 48 fps to double the capture rate? VISION3 film stock - with very low grain and stunning sharpness - would blow viewers away.

Ned Price, VP Mastering, Warner Bros. Technical Perations, responds: "Warner Bros. is scanning A Star Is Born in 6K primarily for restoration and preservation purposes. As a studio, our goal is to have a negative with the maximum amount of information to put back in the vault for archival purposes as well as to be ready for whatever new advances in optical media the future may bring."