There is a growing problem within the CE industry today. The problem is a collaborative one that was created out of ambiguity and laziness between enthusiasts and within the CE industry itself. I am, of course, talking about the widely used "4K" moniker when talking about UHD. The two formats are obviously not the same, otherwise we'd only be calling it one or the other. Part of the problem has been a lengthy wait time, wild speculation on the formats' specifics, and a problem with manufacturers themselves making the two names synonymous with each other.
Like 2K, 4K is a professional format used on the commercial side of video production most often seen by everyday consumers at commercial movie theaters equipped with the latest digital projectors. Unlike UHD, 4K has a different native aspect ratio. A true 4K image (4096x2160) has an aspect ratio of 1.9:1, while a true UHD image (3840x2160) is 1.78:1. We can see here that a 4K panel is actually wider by 256 pixels. This is a trivial number and doesn't do much in terms of overall resolution or clarity of the image. I'm fairly certain that this minimal difference in resolution is what's fueling many of us to call UHD "4K."
This 256 horizontal pixel difference causes at least one major issue when dealing with consumer content. The problem is that almost all television content is presented in a 1.78:1 aspect ratio. If we were to view this content on a true 4K display, we would see black bars on the left and right side of the display to keep that original aspect ratio intact. While enthusiasts understand the reasoning behind this, most everyday viewers would find their TV content annoyingly masked with black bars, very similar to how they find black bars on their 1080p televisions annoying while viewing 'scope films. This is one of the main reasons for choosing 3840x2160 as the next-gen consumer resolution. It makes sense to keep that 1.78:1 aspect ratio as most content made for broadcast TV is presented this way.
True 4K is the resolution specified by the DCI (Digital Cinema Initiative) commercial standard. This is another area where UHD and 4K differ. Much like Blu-ray is the 1080p standard for encoding and presentation, 4K has its own set of standards that the DCI dictates. These standards are high end, resulting in exemplary image quality. While it isn't totally clear yet what kind of video encoding standards the new UHD video format will use, all rumors point to sub-par encoding. DCI 4K uses JPEG2000 video compression, up to 250Mbps video bitrate, 12-bit 4:4:4 video, and a much wider color gamut. HDMI 2.0 will most likely dictate the standards for UHD Blu-ray (or whatever they decide to call it). Unfortunately, HDMI has very little left to give as an interconnect standard. As a result, there is no way to transport the amount of information needed to exceed or even match the 4K DCI standard. Those in the know are under NDA (non-disclosure agreements), which means we won't know the specifics for at least another month or two. Rumors point to 10-bit 4:2:2 video for UHD video content at 24 frames per second and a doubling of the throughput to support higher bitrates.
As we can see, the term "4K" encompasses more than just resolution. I’m going to give everyone who's called UHD "4K" the benefit of the doubt and assume that everyone knows the differences. Heck, I'll admit it, I was one of you. So, if this is the case, why does everyone still call UHD "4K"?
The issue stems from a time where no one knew what the new format was going to be. We've only known for a fairly short time that the new resolution was going to be 3840x2160. This resolution was not the 4096x2160 that enthusiasts wanted. The A/V enthusiast community, including us here at AVSForum, are partly to blame for this naming error. We had way too much time on our hands to gossip, speculate, and more importantly, assume we were going to get a format that would derive from the DCI 4K standard regarding not only resolution, but video compression, bitrates, bit depth, chroma subsampling, color space, etc. This infatuation with wanting the best of the best turned anything next-generation digital video into "4K," even if that isn't what we got. What we now have is an entire industry afraid to let go of that 4K moniker because of how much the name has stuck, even though what we're getting isn't 4K in both resolution and video-encoding quality.
I've noticed many UHD products being described as "4K-UHD." Even the Wikipedia page for UHD now refers to UHD as "4K-UHD." If you go to Newegg or Amazon, many HDTVs and computer monitors have both 4K and UHD in the title. To those who don't know the difference, it can be confusing. If I was shopping for a 1080p HDTV and saw 2K and 1080p in the title, I'd be very confused. If I was shopping for a computer monitor and saw it listed as both 1920x1200 and 1920x1080, I'd be even more confused. Which one is it?!? I’m sorry folks, but UHD and 4K are not the same. It boggles my mind that at least one major manufacturer hasn't called BS on this.
I blame the CE industry for letting this issue continue. UHD is still one of those esoteric topics where all the CE manufacturers need to do is simply change their branding scheme to fix the issue. If you were to stop 100 regular folks on the street to see if they knew what 4K or UHD is, I'd wager that less than 10 percent could give you a correct answer. Sony has flat out said it will not drop the "4K" naming scheme even if its products aren't really 4K. It seems 4K is a much more marketable name than UHD to early adopters.
In Scott Wilkinson's recent interview with video guru Joe Kane, he speaks about the same issue. Kane seems just as upset as I am. But he offers a solution, and it's a fairly simple one. He thinks it could be as easy as getting people to start referring to UHD as "2160p." Kane's reasoning has to do with why we call our Full HD displays "1080p." Kane explains that we have always referenced consumer displays by their vertical resolution and commercial displays by their horizontal resolution. So 2160p could be a great alternative to UHD, just like 1080p, 720p, and 480p were before it. I, for one, agree. It seems like the logical solution here even if it doesn't roll off the tongue as easily as 4K does.
To get the change that’s needed, someone big needs to take a stand and completely drop the 4K naming scheme for home-theater products. I find this issue particularly troublesome because even enthusiasts seem completely content with making the mistake. I guess a good way to sum it up would be to say that the term "4K" already has a meaning—it refers to a resolution and a strict set of rules for presentation. We aren't getting the same resolution or the same set of rules with UHD, so why call it something it isn't? I think we here at AVSForum have an obligation to fix this. We're a large enough community to make a difference. This site alone gets over 2 million unique visitors per month. With enough word of mouth, or more specifically, forum posting, we can turn this thing around. Who's with me?