Advancements in smartphone technology have brought us the capability to pay with just a tap and snap pictures with near standard camera quality, as well as pump out some serious performance thanks to the increasingly powerful mobile CPU's and GPU's that are launched every year. Screens are also getting increasingly larger, and more sharp with visual clarity becoming exceedingly crisp compared to previous model devices. Right now the standard for top quality resolution is Quad-HD, but with Sony's announcement at IFA of the Xperia Z5 Premium, the world is set to receive its very first 4K smartphone. Think about that for a second. A smartphone with a 5.5-inch display packed with the same resolution quality as that of a various large size TVs.
With the ability to record 4K content through most of Sony's top-tier smartphone cameras, and the arrival of more 4K content, it's no doubt that 4K screens were going to make it to smartphones some time, but this soon is something many probably weren't expecting. While it might look good on paper and sound good when you hear about it, is it needed? Are 4K smartphones overkill? To the majority of the general public who own a smartphone, the answer is probably a solid "yes." There are those out there however, that are likely chomping at the bit to get their hands on a phone with this kind of screen resolution, whether they'll be using it very often or not.
Sony's choice of a 4K screen is also surprising as they have typically stuck with Full HD on every other top-tier device, completely skipping over Quad HD. Even Quad HD to some is over the top. Having personally used both QHD phones like the LG G3 and the Samsung Galaxy S6 and Galaxy S6 Edge, comparing the screens to my daily driver: Sony's Xperia Z3 with Full HD resolution, I could notice little if any difference in sharpness or crispness of the display. Sure, Samsung's screens were noticeably brighter thanks to the Super AMOLED panel, but icons, pictures, videos, and even games, none of them looked any more sharp on a QHD display than they do on my current Full HD device.
Whether or not you find 4K smartphones to be something we need or just a luxury is also personal opinion. Some will undoubtedly love this new feature and hope for more smartphone OEMs to follow the same route. Others will think it is simply overkill and an unnecessary decision that will only cause smartphones to rise in cost for the consumer, and in an age where smartphones for a low price but still carrying excellent specs seem to be the popular choice for many individuals, high-end extremities may not fit in so well. There's also the matter of whether or not anyone will be able to pick out the extra rich details that 4K is supposed to bring to the table. On a display size this small (5.5-inches) many think that it won't be possible to see the benefits of 4K, and they may be right. The pixels are already packed so tight into the size of smartphone displays that it's almost impossible to see them with QHD and even Full HD screens. So there lies the question of if we need a 4K screen to make things more sharp. There's a huge difference between watching or viewing 4K content of any kind (which is scarce at the moment as it's still a relatively new technology for consumers) on a large TV or monitor for things like 4K videos or 4K gaming, and having access to some of that same content on a smaller smartphone display.