What is 4K? Difference between a Full HD image and a 4K image?

What is 4K? What is the difference between a Full HD image and a 4K image?

A standard TV picture is normally delivered in FULL HD by radio antennas (rake antennas) and boxes. We will talk about it in a future blog. But new TVs and projectors talk about 4K definition: what is 4K?

4K is a superior image quality, designed for very large televisions and large projection screens. In fact, if the image of your television or video projector is larger, viewer’s eye will see the pixels that make up the image. The manufacturers have therefore decided to multiply the number of pixels displayed, so that the image is more precise and defined.

Specifically, a standard FULL HD image contains 1080 lines of pixels in height (that’s why we speak of “1080p” image) and 1920 pixels on each of these 1080 lines. So we have an image of 1920×1080 pixels.

In 4k, the manufacturers decided to multiply all the pixels. A 4K image therefore displays not 1080 lines but 2160 lines, not 1920 pixels per line but 3840 pixels. The total image thus displays 2160x 3840 pixels, which is 4 times more than in standard FULL HD.

You will find now projectors in “4K”, just as you find televisions in 4K. This is called “ULTRA HIGH DEFINITION” or “ULTRA HD”.

What about audiovisual content?

But as usual, 4K audiovisual content are rare. Forget DVDs (only 720 pixels per line), prefer blu-ray 4K that are now available. Few TV box or VOD subscriptions are available in 4K. https://www.design-screen.com/en/projection-screen-images-installation/

And very often, there is a gap between the promise of operators and the actual flow actually received in our homes. I found in hearts of cities such as Nantes or Tours that the image displayed is painfully available in High Definition, and even very often lower (in 720p). Saturated networks, fiber deployment, ADSL connections , subscriptions at low prices, so many reasons why I advise to check your actual flow. https://www.zdnet.fr/services/test-bande-passante/

A trick? If you want to have a good reception, remember that a good antenna rake will bring you a beautiful image in FULL HD high definition, and in addition free and without subscription! You will just need a small box TNT that will transmit the signal to your projector. A good 4K projector will extrapolate the received signal and display it in 4K ready: at last enjoy beautiful images on very big projection screen! 4K TNT France should arrive in 2024.