Sony has launched their first premium phone of 2015 -- the Xperia Z5 premium, the world's first smartphone to feature 4K display. The phone features a 5.5-inch display with a resolution of 2160×3840 pixel resulting in a whopping pixel density of 806ppi.

Last year, we saw the rise of QuadHD 2K display on smartphones like LG G4 and Galaxy S6, but no one anticipated we would see the 4K display on a smartphone this year. There is going to be a big debate on whether the 4K display on a smartphone is a good thing since such a high resolution won't provide any visual advantage over QHD or even 1080p. Moreover, the 4K display doesn't make sense if you take battery life into perspective.

Fans React to 4K display on a smartphone:

Apart from the 4K display, the Xperia Z5 Premium sports a new camera sensor -- Sony's IMX230, which is a 23MP 1/2.3" sensor with 1.12-micron pixels. The lens used has a 35mm equivalent focal length of 24mm and an aperture of F/2.0. The camera can capture 4K videos at 30fps with improved Intelligent Active Mode and SteadyShot technology for smooth, sharp videos at day and at night.  There is a 5MP  front shooter with an Exmor R sensor that has a 25mm wide-angle lens for group photos.

Under the hood, the Xperia Z5 Premium sports a latest and greatest Qualcomm Snapdragon 810 octa-core processor with big.LITTLE architecture for better balance in performance and battery life. The Z5 Premium uses a stainless steel frame and comes with IP65/68 rating for dust and water resistance.

Sony Xperia Z5 Premium Full specs:

• 5.5-inch IPS LCD @ 2160×3840 pixels, 806ppi
• Qualcomm MSM8994 Snapdragon 810
• ARM Cortex A53 1.5GHz quad-core, ARM Cortex A57 2.0GHz quad-core
• Adreno 403 Graphics
• 3GB LPDDR4 RAM
• 23MP rear camera, autofocus, LED flash
• 5.1MP front-facing camera
• 32GB internal storage Up to 200GB via microSD
• LTE Cat. 6, Wi-Fi 802.11 a/b/g/n/ac, dual-band, WiFi Direct, DLNA, NFC, Bluetooth 4.1, A2DP, apt-X, ANT+ support, GPS with aGPS, GLONASS/Beidou
• IP68 certified
• Fingerprint Sensor
• 3430mAh Li-Ion battery
• Android 5.1.1 Lollipop
• 154.4 x 75.8 x 7.8mm (dimensions)
• 180 grams (weight)
• Colors: Black, Gold or the unique Chrome option

Sony has also launched Xperia Z5 and Xperia Z5 compact. The Xperia Z5 has a 5.2 inch 1080P display whereas the Z5 compact has a 4.6 inch 1080P display. Both these handset sports the exact same hardware specs underneath -- the same processor, RAM, and camera sensor.

The Xperia Z5 Premium will be available for purchase starting from November and will come in single and dual-SIM versions. The Xperia Z5 and Z5 compact will be available earlier in October. Sony is yet to confirm on the pricing of these phones.