Why has 4K suddenly become the standard, you may ask? The details provided by the Genval les Dames team are quite technical, but nevertheless clear and instructive. “Everyone,” explains Paul Englebert, “agrees that the original definition of 35mm film is close to 4K (4000 dots x 3000 lines, the equivalent of a 12-megapixel photo). However, in order to access current digital post-production, the rushes shot on film are scanned (digitized) in 2K (2000 points x 1500 lines, the equivalent of a 3 megapixel photo). Why did we stay there? Because 2K images produce files that are one-fourth the size of 4K images, and because most scanners are not capable of achieving resolutions greater than 2K.
Unfortunately, once this operation has been performed, the difference in definition with images filmed by digital cameras offering a native definition of 2K or HD is no longer really visible. In addition, to be shown in theaters in film form (on 35mm prints), the digitally produced post film must be transferred to film, and most of the machines performing this operation work from 2K images. All of these reasons mean that films shot on 35mm are reduced to 2K definition when released.”
Adopting 4K is simply a matter of maintaining consistent quality from start to finish. CQFD. And where does it take place? Well, at home!