4K phone screens: madness, or clearly the next big thing?

Screens are set to get crisper but it may be a needless tech advancement

4K Phone Screens madness or clearly the next big thing







At a basic level, all screens have a resolution, which is expressed as the number of horizontal pixels times vertical pixels – for example, 1280 x 720, meaning that there's 1280 rows of pixels horizontally, and 720 vertically.

In theory, the higher the resolution, the crisper and less blurry the image. The resolution is often abbreviated to a snappier name – for example, the 'HD' logo that's slapped on most TVs these days. High Definition means a resolution of at least 720 pixels vertically, and 'Full HD' is a minimum of 1080.


The LG G3's QHD is stunning - but 4K will push quality further



iPhone 4: the original Retina display

The allure of higher-res screens is simple: more pixels should, in theory, mean a sharper, clearer, more detailed image – the effect Apple had with the iPhone 4 when it introduced the first 'Retina Screen'.



iPhone 5s
Apple believes the human eye can only see 326ppi

Because smartphone screens are so physically tiny compared to TVs, the PPI is incredibly high – up to 530 on phones like the LG G3.

Although that might sound like improvement, the human eye stops being able to make out a screen's individual pixels after a certain point – and after that point, increasing the resolution further won't really do anything of benefit.

According to Apple, that cut-off is 326 PPI for a smartphone. (Your eye's 'max' PPI depends on how far away the device is – hold press your face right up to a 4K TV, and you could probably see the individual pixels, but not so for a smartphone.)

Experts, such as DisplayMate's Raymond Soniera, peg that number a little higher – up to 600PPI for people with freakishly good vision.