As 4K displays are now coming out, a common debate between people online has been about the benefits of 4K compared to HD in a normal viewing environment. Many people will say that 4K looks amazingly sharp and it’s impossible not to see the difference, but many others will say that in a regular living room, with a regular sized screen, you really won’t see much of a difference.
Update July 3rd, 2013: Read more about HiDPI and 4K Display use cases and benefits. My new article compares smartphones, tablets, laptops, monitors, TVs, and projectors to see where high-resolution provides the most visible benefit.
Most people who have seen 4K to this point see it at trade shows, or at stores that have dedicated displays for it, and not at home with normal content.Many times these are setup to only allow you to be so far away from the screen, which makes 4K look great, as it really does look amazing from 3′ away. They also use special content to show off 4K, as you can’t go to Amazon or Best Buy and order a 4K movie right now. One company at CES was showing off their 4K TV using a 5 minute demo from Dreamworks, which they told me was hundreds of gigabytes as it was totally uncompressed. That kind of content won’t be available to anyone at home anytime soon, and makes for a completely unfair comparison between HD and 4K.
There is a chart from Carlton Bale available that shows when you might be able to see the difference with 4K compared to 1080p or 720p, but I decided to make my own 4K calculator that gives you just a little more detail. Using this you can enter your screen size, your distance from the screen, and your vision to generate some numbers for you. The information this will provide you is:
- The Pixels Per Inch for 480p, 1080p, and 4K signals based on the screen size.
- The maximum resolution that you can discern with your vision based on the distance from the display
- The ideal 4K screen size for your distance, which is the smallest screen at which point you can resolve all the pixels
- The ideal distance from a 4K display of your specified size, which is how close you need to sit to resolve every pixel
- The amount of extra resolution that would be visible on a 4K display compared to a 1080p display based on your screen size and distance. The maximum amount would be 300%, and the minimum is 0%
I’ve also created a chart, seen below, that gives you a quick glance to see what the ideal viewing distance is for a 16:9 display based on size and resolution. This is based on 20/20 vision, and the viewing range for each resolution is the distance you can sit from that TV and see more detail than a lower resolution, and are not close enough to see the extra detail in a higher resolution screen. So with a 50″ 1080p display, if you are closer than 9’9″ you will see more detail than a 720p display, but if you are more than 6’6″ away, you couldn’t see any more detail on a 4K display.
This calculator does make assumptions about vision and arc minutes, but those that I talked to said this was as good of an assumption to make for human vision as anything else. If you think that it is off, you can easily adjust the vision to 20/15 or 20/10 to make it more accurate to you. This also will let you calculate for devices like cell phones and tablets, that will often be placed much closer to your face, to compare them to a 4K display that is much further away. One more assumption is that you have a 16×9 screen, though other screen ratios may be supported in the future.
Hopefully this will help you to determine if you will see much benefit from 4K in your situation, as well as making it easier to compare devices like a cell phone or tablet that you hold very close to your face to a TV that likely sits across the room from you.