You've probably heard the term "4K". Maybe, in a colossal fit of boredom, you've wondered what it means. Rest assured, dear reader, I will explain and tell you why you should care.
The HDTV you have at home is made up of a two-dimensional grid of pixels that together show you the basketball game in crisp high definition. That HDTV has 1920 pixels across and 1080 pixels down for a total of 2,073,600 dots of awesome also known as "1080P". Your old TV, the one that's now in the garage collecting dust had, at most, approximately 640 pixels across by 480 pixels down - a hilarious and measly 307,200 dots. How did we manage?
Compare the above to today's 4K displays: 4096 by 2160 equals 8,601,600 dots! The "4K" moniker comes from the approximately 4000 pixels that make up the horizontal resolution of the image. Now wait, put down the slide rule for a second. You're right: these aspect ratios are all different. So far we've talked about 16:9, 4:3, and 19:10 ratios.
Unless you're making or watching a Major Motion Picture(TM) you won't see true 4K and its weird 19:10 aspect ratio. You are going to see (and want) something else called Ultra High Definition (UHD) at 3840 by 2160 which has a ratio of (slide rule ready?) 16:9 - just like today's HDTVs.
Why do more pixels matter? Consider the humble letter S and its curves projected on a classroom screen. As you project a 1080p image ever larger on screens in classrooms, lecture halls, and the like the pixels that make up the smooth shape get equally large resulting in a grainy image. Rather quickly you've degraded the smooth curves into a smear of pixels.
You may have noticed that a 1080p computer desktop viewed on a large screen from ten or more feet away makes for some rather small letters. To combat this Kontek frequently recommends that you set your computer's resolution to the smaller 1280 by 720 resolution (720p) and let our scalers make the image larger. This, essentially, lets the projector or flat screen display use more pixels to draw the same image. More pixels means sharper text.
I suggested earlier that you will prefer the Ultra HD resolution of 3840 by 2160 in part because it's easy to scale up and, thus, improve a 1080p image to Ultra HD. You simply double the 1080p signal in each dimension. Where once you would see a single pixel you now have four and the result is a much sharper final product.
But it isn't all about the dots... While 1080p HDTV can hardly be accused of being lackluster in the color department, UHDTV has even more fruity flavors on offer. A 4K signal can deliver a 12-bit color depth compared to 8 bits for most 1080p content. Have I lost you? Hold on tight.
Eight bit color means that you have 256 shades each of red, green, and blue or 16,777,216 possible colors. Twelve bit color depth (4096 shades each) means a total of more than 68 billion colors! Crayola has some catching up to do. If you don't believe that the color changes are important try asking a cardiologist if she thinks that subtle differences in red make a difference in her work.
For more information on the color advantages (Nerd Alert!) see this excellent article at shutterangle.com.
One of the lines we hear a great deal is "But there isn't any content for 4K!" - False. Many modern computers can output Ultra HD via DisplayPort or HDMI. You may not want to do this quite yet because of the small-font problem but scale up a 1080p resolution and prepare to be amazed.
Jonathan is one of Kontek's control system programmers. He has been with Kontek since 2005.