4K vs 8K: Understanding your TV screen’s resolution

At this point, pretty much all of us know that a ‘Full HD’ or ‘1080p’ TV is just not as good as a 4K TV. Whether it is about colour recreation, the crispness of the details, the contrast and brightness, or just about anything else.  

But here arises another question. What about 8K resolution? Is it going to replace 4K, just as 4K replaced 1080p? Or have we finally reached the limits of perceivable resolution as some would suggest? Let’s take a closer look at the tech to try and understand why and when 8K matters, and why 4K isn’t going away anytime soon.

Understanding pixels: FHD vs 4K vs 8K

Any digital image you see is made up of tiny, coloured dots called pixels. The more the number of dots that make up an image, the higher its resolution. 

ALSO READ: What is 8K TV? 

A 1080p display has 1920×1080 dots or pixels, which equates to 2,073,600 or two million pixels. A 4K display has 3840×2160 dots or pixels, which is roughly 8.3 million pixels, and an 8K display has 7680×4320 pixels, or about 33.2 million pixels. 

Essentially, 4K has four times the number of pixels as 1080p, and 8K has four times the pixels as 4K.

Resolution vs density: When does 4K matter?

Resolution simply refers to the number of pixels in a given display while pixel density is the number of pixels per unit area of the display. For a sharper image, you need a higher pixel density, and a higher resolution is simply a consequence of a higher pixel density. 

Think of it this way, you can buy a 27-inch monitor with a resolution of Full HD or 4K. Obviously, the 4K monitor will show a sharper image. Calculating pixel density explains why.

Screen size vs pixel density

On a 27-inch screen, an FHD image has a pixel density of about 82 pixels per inch (PPI). A 4K monitor, on the other hand, doubles this to 163 PPI. If the screen size is the same, a higher resolution display will have a higher PPI or pixel density and will present a clearer image. 

Now let’s take another example. You’re buying a 55-inch TV in a 4K resolution. The TV’s PPI comes to a measly 80, which is even lower than what we saw on the 27-inch FHD display. But why does the TV look so sharp regardless, and the 27-inch monitor so blurry? Also, why does a relatively compact 6.3-inch iPhone 16 Pro display need 458 PPI? 

Viewing distance vs pixel density

Lastly, one of the most important factors affecting how we perceive sharpness is viewing distance. An iPhone is held mere inches from your face, a foot or two at best, which is why it needs such a high pixel density. Since it’s closer to your face, you perceive more detail and thus you need a higher PPI to compensate. 

A 27-inch monitor is ideally placed about 3-4 feet from your eyes, where the low resolution of 1080p is only a minor issue and 4K seems stunningly sharp. Up the size to 55-inch as in the case of a TV, and it’s recommended that you sit about eight feet away. At this distance, the low PPI of 80 shouldn’t be an issue, and the TV looks just as sharp as your 458 PPI iPhone does at one foot.

4K vs 8K, which is better?

1. Clearly, the choice of resolution comes down to two factors: screen size and viewing distance. Assuming an average TV size of 55-inches and a viewing distance of eight feet, there will be no discernible difference between a 4K resolution and PPI of 80 and an 8K resolution and PPI of 160. If you’re getting a much larger TV or perhaps are forced to sit closer to the TV, then you might want a higher resolution. For most people, this is not the case.  

ALSO READ: 10 best smart TV brands in India in 2024 

When you then factor in the cost of an 8K TV – much more compared to a 4K TV, the lack of 8K content, and if you’re a gamer, the difficulty in rendering games at 8K resolution, you may notice how a 4K resolution display today, is good enough. In fact, 8K only makes sense in certain specialised use cases such as digital backdrops and billboards where you have hardware and content that supports that resolution. 

Sure, there might come a point when 8K fully replaces 4K. But then again, that is in the future. For now, one should consider investing in display quality – OLED, mini LED tech, etc. – rather than resolution. By the time 8K goes mainstream, your current TV will likely be old enough to warrant an upgrade anyway.