The Only Thing Clear about 4K Debate is its Lack of Resolution
"A screening of "Reach for Me," an independent film being billed as the first feature to be shot and posted in 4K resolution, was projected in 4K for a full house Monday at Los Angeles' Landmark Theater.
Helmed by LeVar Burton and starring Seymour Cassel and Alfre Woodard, the film used the Dalsa Origin II camera, went through a post process at Post Logic and was screened with the Sony SXRD projector. Audience response was positive.
Still, there are a lot of varying opinions about 4K, an image resolution that represents four times the amount of picture information found in a 2K file, which is the most commonly used resolution for digital cinema production and distribution.
The topic is about much more than counting pixels. Its complexity requires a look at numerous aspects of imaging. More data means more complexity and increased expense. There also are independent issues when it comes to addressing 4K for production, post, projection or archiving.
"My own personal view is that resolution constitutes only one of several important factors, including color, contrast, light levels, reliability, affordability and ease of 3-D adaptability," National Association of Theater Owners president John Fithian said about exhibition.
Meanwhile, many industry experts — all deeply committed to the goal of image quality — have been examining 2K and 4K imagery from all angles and distances and on a variety of display systems. Even within these circles, many say that the quality difference between 2K and 4K is substantial, while others question whether there is a noticeable difference on today’s display systems.
All of this has left industry pros asking whether 4K is practical or necessary.
For Chris Cookson, president of Sony Pictures Technologies, archiving and exhibition are key reasons the industry should move to adopt the format.
"The 2K master has less information than the original film did," he says. "For the last 100 years, we're saving the original negative. We need to be aware of what we throw away and the implications of the decision we make. ... Having something that is only as good as today's exhibit capability is not a limitation that we have ever had before."
An immediate concern for Cookson is the launch of the Blu-ray Disc format. "A lot of studios are having to remaster stuff that they did just three or five years ago," he said. "Blu-ray is so clear, and the new 1080p sets are so sharp that what they thought was good enough five years ago doesn't pass muster today. And I don't think we are done yet."
With 4K masters, he suggests, "if home theater takes one more step up, we can step up with it."
Still, post houses report that the demand for 4K remains limited. Even EFilm, which has been bullish about the format, expects to do maybe five 4K digital intermediates this year -- about 10% of its total.
According to post house execs, studios generally are unwilling to pay extra to work with 4K files, which require greater network bandwidth to manage the data.
A movie posted in 2K uses nine to 10 terabytes of working storage, and Efilm president Joe Matza estimates that the final project is around 2.5TB, depending on length. He suggests that when that goes to 4K, filmmakers are looking at 25-30TB of working storage and 9-10TB for the final project.
To understand the size of these files, here's a sometimes-used comparison: If you were to store a single 2K frame on a desktop computer, it would equate to a Word document more than 600 pages long. 4K contains four times as much information. (Keep in mind this is a general comparison that doesn't weigh factors such as compression or bit depth.)
Matza believes things are starting to change, however.
“The cost of storage is continuing to drop, and the motion picture business is the beneficiary,” he says.
Obviously, this only scratches the surface of some aspects of a complex topic. As business, creative and technological issues collide, resolution will continue to be discussed and debated — and new factors will be introduced as developments occur. Case in point: NHK already is demonstrating its developing Ultra-HD technology, which includes 8K resolution.
Getting Clear on 2K and 4K
Today's commonly used resolution for feature film digital postproduction and mastering, as well as for digital cinema production.
2K
Horizontal pixels: 2,048
Vertical pixels: 1,556
Megabytes per frame: 12
Recent example: "Iron Man"
4K
There is a growing availability of production and post tools that support 4K. Sony says there are about 200 4K d-cinema projectors in North America.
Horizontal pixels: 4,096
Vertical pixels: 3,112
Megabytes per frame: 48.5
Recent example: "Reach for Me"
By Carolyn Giardina, The Hollywood Reporter