How to find the right size TV
How to find the right size TV? The key to determining the right size and resolution you need when buying a new TV lies in the natural resolution of the human eye. The clarity of vision is also referred to as visual acuity and is limited.
There is only so much detail someone with 20/20 vision can see. Although the exact value depends on a number of different factors, such as the contrast between elements, 60 pixels per degree is seen as an accepted value.
When sitting in front of a TV, the screen’s pixels will cover a certain angle of the viewer’s vision. When moving closer to the TV, the same amount of pixels will now cover a wider angle, which means the number of pixels per degree is reduced and individual pixels will be easier to see the closer one moves to the TV. When moving further way from the screen, the opposite is true until the number of pixels per inch exceeds 60.
At that point, the human eye cannot differentiate between individual pixels and moving further away will not increase clarity, it will simply make the screen appear smaller.
The chart below shows the connection between screen size, resolution and viewing distance. Thicker lines represent optimum viewing distances for 4K Ultra HD TV, 1080p Full HD, 720p HD and 480p resolutions.
For example, a 55-inch Full HD TV is best viewed from 7 feet away. At that point, the optimum number of 60 pixels/degree is achieved, and the picture appears as sharp as possible. Moving closer would make the picture look blurry or pixelated and moving further back would make the TV screen appear smaller without any improvement of image quality.
So, when does a 4K Ultra-HD TV make sense? For most people sitting at a comfortable distance away from the TV, a 4K-resolution screen is not necessary. It only makes sense when sitting very close to the TV to achieve a fully immersive experience similar to an IMAX cinema.
When choosing a very large screen, such as an 80 or even 100-inch TV, the higher resolution will have advantages, as the image is a lot larger.