Sony has skipped 2K and gone straight to 4K for the launch of the world?s first UHD 4K smartphone, which has four times the number of pixels of Apple?s iPhone 6 Plus.


The new Xperia Z5 Premium ?super flagship? smartphone has Sony?s new 5.5in 4K display, which has a pixel density of 801 pixels per inch (ppi), and leads a new range of Z5 series smartphones.

The higher the pixel density the sharper the screen; it is the basis for which Apple sells its ?Retina? screens, but others, such as Samsung and LG, have opted for 2K displays with pixel densities at 577 and 538ppi respectively.

Apple?s iPhone 6 Plus with its 5.5in 1080p display has a pixel density of 400ppi, while Sony?s previous smartphones had a maximum of 423ppi.

The back of the 5.5in Z5 Premium is mirrored to differentiate it from the frosted glass of the Z5 and Z5 Compact, but will undoubtedly become a fingerprint magnet.

Despite having a super-high resolution, Sony promises up to two-days battery life, using the same image processing and power saving technologies it used within its Z3 and Z3 Compact, both of which had two-day battery lives.

The Z5 Premium has 32GB of storage, 3GB of memory and runs Qualcomm?s octo-core Snapdragon 810 processor, which caused overheating issues in several smartphones, including Sony?s Z3+, and could only record 4K video for less than a minute before overheating.

The smartphone will also use Sony?s first new smartphone camera sensor in two years, which integrates phase detection technology from the company?s Alpha cameras for the world?s fastest focus time of 0.03 seconds.


?Why is 4K needed? There are 76 display resolution variations but only nine content resolution variations, none of which include 2K, so if you?re going to go higher than 1080p, 4K is the answer,? said Takao Yagi from Sony?s Xperia display technology group in Japan.

Whether a resolution as high as 4K on a screen as small as 5.5in makes a material difference for consumers remains to be seen.

The 5.5in Z5 Premium will be joined by a standard 5.2in Z5, the successor to Sony?s Z3, with a 1080p screen with 423ppi and similar specifications to the Premium.

Sony will also update its smaller, top-end smartphone range with the Z5 Compact, which promises the same performance as its larger smartphones but in a more manageable frame with a 4.6in 720p screen.

The 4.6in Xperia Z5 Compact promises to be easier to use due its smaller size.

All three smartphones are waterproof and will have Sony?s new fingerprint sensor, which is hidden under the power button on the side of the phone ? the first fingerprint scanner not to be placed either on the front or the back of the smartphone.

?People press the power button 100 times a day, having a fingerprint sensor under it on the side means it?s not awkward to activate and keeps the phone secure,? said Jun Makino from Sony mobile.

The fingerprint scanner is on the side of the phone under the power button, rather than on the front or the back as with Apple, Samsung or Huawei smartphones.