Can someone explain 4K to me?

I simply do not understand the point of 4K.  Yes, it is an incredibly awesome breakthrough in technology and video will always continue to get better, but is it actually necessary?  I can understand that people who own/manage movie theaters would want 4K resolution projectors or even people with home theaters, but for the average consumer, it is probably not necessary.



People like charts, so here's a chart for you:

CarltonBale.com

Assuming you fall into the category of "average consumer" and you buy TV's in the 20-80 inch range, what this chart says is that unless you plan on sitting less than five feet away from the TV, buying a 4K resolution TV is a waste of money.  At more than five feet away, a person (with 20/20 eyesight) will not be able to notice any difference between a video in 1080p vs. a video in 2160p (4K).

Aside from that, there is also the issue of having almost nothing to watch in this spectacular resolution.  Of course this issue will diminish with time, but it is going to take a while, at least a few more years.  By that time, buying a 4k TV will be more affordable and better quality anyway; certainly if you are thinking about buying one, wait a few years.  Rendering videos in 1080p takes a long time and rendering a video with four times the data will only impede the process.¹  With that being said, it is not likely that many older videos and movies that were shot with analog cameras will ever be converted to 4K resolution.  Most analog movies have already been converted to HD format, either 720p or 1080p, and the conversion process is so time consuming that, unless the movies were originally converted to 4K and then downgraded to HD resolution, those movies are not likely to go through another conversion process.²  Therefore, 4K resolution is essentially reserved for future movies.  Of course, as with playing a standard definition (480p) video, such as a DVD, on a 1080p TV, the video is scaled up to fit the TV size when playing a 1080p video on a 4K screen.

Before I move to my next main point, I want to mention file sizes.  Video file size depends on many things about the video.  1080p video shot with the Canon T3i will take up about 1GB for every 3 minutes shot.  Since 4K is four times the size of 1080p, it would be a valid assumption that 3 minutes of 4K video would require about 4GB of space.  After post processing, the final video size is generally reduced by a considerable amount, depending on export settings, but 4K movies are going to take up much more space than other HD movies.  Larger sizes also means they will be harder to stream, especially on a slow internet connection. Extra: The First 4K Movie is 160GB.

Another point to be brought up is about the hardware.  Current hardware, and hardware being sold inside 4K resolution TVs, is not even powerful enough for the TV to play a 4K video in all its glory.  HDMI is the standard for transferring HD video from the player to the TV.  Currently that is HDMI 1.4; this was built for HD video, not Ultra HD video (category for 4K or 2160p), HDMI 1.4 doesn't have enough bandwidth to carry all the data 4K requires in the time 4K requires.  HDMI 2.0 is rumored to be able to solve this issue, but this is a technology that is not here yet.³  Once the rumored HDMI 2.0 does come out, that means that new hardware will be required in the current 4K TVs that are being sold now.  While it is possible that there will be backward compatibility for HDMI 2.0 cables to work in HDMI 1.4 ports, the problem with speed still exists.  The HDMI 1.4 ports that are built into the TV itself will not be able to transfer the 4K data fast enough, so simply buying a new HDMI 2.0 cable when it comes out will not solve the problem—you'll need to buy a new TV (or I guess you could manually upgrade it if you knew how).

Overall, I just do not understand what all the hype is about.  Sure, it is super cool that you can get so close to the screen and not be able to see the pixel grid, but when watching a video, a person will not be that close to the screen anyway.  If you are looking to buy a 4K TV, I would advise that you wait.  Wait for improvements and wait for HDMI 2.0 at the very least.  The only places I can imagine a 4K screen would be useful and preferred over 1080p screens are in movie theaters, home theaters, or if being used as a computer monitor.  Other than that though, there is not much point for a person to buy a 4K TV.  Maybe in the future there will be more of a point, when DVDs are no longer being made and everything is either Blu-ray or 4K Blu-ray (oh yeah, video players need to be updated too, Blu-ray discs do not have enough space to put a 4K movie on them, so a new disc called 4K Blu-ray is in development).  Then again, by that time, everything might just be downloadable and discs will be a thing of the past.

What do you think about 4K videos?  Let me know in the comments below.

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¹The time it takes for a video to render depends on many different factors, including: processor speed, the number of cores being used, hard drive speed, compression settings, codecs, and more.
²Because of the nature of analog film, it can be converted to extremely high resolution and not be pixelated.  With already digital film though, the best that can be done is an upscaling process in which a computer basically guesses what should be in the extra pixels, usually creating a pixelated picture.
³To read more about the relevant details of HDMI 1.4, see "4K video can be choppy" and "4K video color is lacking" by following this link.