4K technology has only now exploded onto the consumer and production market, eclipsing Full High Definition items with 4K mastered films, 4K Ultra High Definition TVs, 4K projectors, monitors and cameras, and 4K content available for streaming on the likes of popular sites like YouTube.
For commercially available purchase, 4K is the top of the line technology dominating all aspects of cinema, from production, post-production, theatrical screening, and home entertainment.
The technology, however, has actually been around for quite some time. Twenty-two years to be exact.
Recall the quaint story of a young woman living with a group of rambunctious dwarfs, the film version animated entirely by hand. Snow White and the Seven Dwarfs, which was released in 1993, was the first film to be digitized and processed in 4K. For its release, however, technology of the time did not support 4K resolution, so the film was downgraded to a smaller digital resolution.
In fact, films shot on analog, particularly 35mm film, exceed the resolution of 4K, stretching into the still commercially inaccessible realm of 8K. This is perhaps why analog projection has survived so long despite the advent of digital cinematography and processing (oftentimes with digitally processed films being printed back onto 35mm for screening – although this technique is quickly changing). Only in recent years has digital technology very slowly figured out how to mimic looks on the same level as celluloid in the theater.
The term “4K” was first coined by the Digital Cinema Initiatives, the professional standardizer of the specs for production and digital projection. Technically speaking, 4K means the resolution of 4096×2160 (for digital cinema) and is stands for the horizontal pixel count of about 4000 pixels. 4K is also conveniently four times the previous standard for digital edition and projection of 2048×1080. As for encoding, 4K is defined by having a DCI stream using JPEG2000 with a bit rate of 250bps and 12-bit 4:4:4 color depth.
The terms 4K and Ultra High Definition (UHD) are widely used interchangeably, but UHD is actually a subset of 4K with a resolution of 3840×2160 for consumer display (think TVs and monitors; even discs labeled ‘Mastered in 4K” are not true 4K, as they are merely upgrades from Full HD 1920×1080 resolution). There are even at least twenty smart phones that have 4K capture and playback ability. While UHD technology is at the forefront of the market, there is a lull on 4K content actually available for viewing. Alongside YouTube, Netflix offers 4K streaming (10 films, 4 documentaries and 5 shows), as does Amazon Instant Video, UltraFix, Samsung UDH Video Pack 2, M-Go, Comcast (only 4 NBC shows) and DirecTV (just 20 films).
If 4K has been around for so long, why isn’t there more content available?
Professionals in film production twenty years ago just didn’t anticipate that UHD technology would take off the way it has. Processing in 4K and then downgrading for exhibition and distribution, as what happened for Snow White, was common practice for thousands and thousands of films. Source material that begins and ends in 4K is far and few in between. The equipment being used for production and post-production exceed Full High Definition, but distribution and display of 4K is still growing. It is still common practice for films to be shot and processed using 4K (the camera leaders of the pack being Sony and Red Digital Cinema), but then downgraded to 2K resolution for the final product.
There are a plethora of pros for shooting in 4K and distributing in HD. Many argue that derivatives of 4K source material in 2K resolution will look better than derivatives of 2K source material in 2K resolution. 4K compressed is also said to look better than 2K compressed. Sharpness, with simply more pixels (8 million versus 2 million), makes a huge difference. Better color precision of 4K, as a result of oversampling and downscaling larger, lower-bit-depth frames into a higher-bit-depth frame, resulting in increased color control, is also an advantage.
In post-production, 4K offers more flexibility. Processing 4K material allows numerous scaling options and cropping without losing any resolution if the final export will be in 1080p. High quality film stills can be made, as they are pulled from high resolution to make high DPI (dots per inch) RAW stills directly from footage. For film and television, 4K acquisition can “future proof” productions – that is, to be able to distribute in 4K when the consumer market for home entertainment catches up with the acquisition technology. Digital projection is certainly getting there, with over 90% of the world’s theaters having already converted from analog. 4k is quickly becoming the new HD, and 1080p is the becoming the new standard definition. The only downside is that in post-production, 4K entails more data to move, process, and store (four times the pixels of HD means four times the data to lug around), all of which is rather costly today. But the hope is that costs will diminish over time as storage technology catches up and 4K establishes itself as the norm.
The inevitable move towards 4K in all spectrums of cinema and entertainment has already taken off. There’s no going back now.