​Sony Xperia Z5 Premium review: Is the world ready for a 4K phone?

This phone has appeared in our Top Rated Android Phones in 2016 list, Best budget smartphones 2016 list and Which phones have the best cameras? list.

A single hand holds 8.3 million pixels. This is what makes the Xperia Z5 Premium, the recent flagship from Sony, one of a kind.

Understanding the feat requires a quick study of the television market. Full HD televisions have 2.07 million pixels with screens as large as 55-inches. Sony’s smartphone has four times as many and its screen measures 5.5-inches.

Crammed into every inch is 801 pixels — almost twice as many as Apple’s iPhone 6s Plus. Packing more pixels closer together paves the way for photos, videos and games that are clearer. Hold the Z5 Premium close and you cannot see the individual blocks that make up an image.

Sony is the first company in the world to take the emerging 4K television technology and plant it into a smartphone. Debate surrounds the validity of 4K technology; how will ordinary content look on the pixel-rich screen and what will happen to the phone’s battery life?

Many of the display technologies found in the Z5 Premium hail from Sony’s television department. The lineage between this smartphone and the company’s $12,000 flagship television are undeniable. Both have deep black displays, Sony’s proprietary suite of imaging technologies and upscaling engines.

The problem with 4K televisions has to do with the lack of content supporting the standard. Most manufacturers try to improve the quality of the content available by using upscaling engines, but like rubber bands that have been stretched too far, the resulting image often looks as though it is tearing on a large enough screen.

None of this happens on the Xperia Z5 Premium. The size of its 5.5-inch screen is too small for any artifacts to be visible once the upscaling engine has done its work. Ordinary high definition movies and games appear organic, as though they were 4K by design, and then there’s the time you load the Z5 Premium’s microSD card with a 4K movie.

TimeScapes is a 9.7GB movie recorded in the same 3840x2160 resolution as the smartphone's display. Watching it on the smartphone brings about a sense of appreciation for what Sony has accomplished. It’s as though you’re staring at a high quality photo, only better, because a backlight imbues it with a gentle glow.

All that is left is the matter of battery life. Screens demand the most from a smartphone’s battery, and increasing the resolution makes them more energy intensive. Sony’s response to this quandary involves increasing the battery’s capacity and refining the smartphone’s economy.

Integrated into the Z5 Premium is a large 3430 milliamp-hour battery. During our seven days of testing, with the energy saving mode enabled, the Xperia Z5 Premium averaged more than a day’s charge at 26 hours. Watching a 4K movie with the brightness amped to max would deplete the battery much quicker, but the Z5 Premium can be used as an ordinary smartphone throughout the course of a day — easily.

And this is the prevalent theme of Sony’s flagship: it is a cutting edge smartphone seemingly free from compromise.

The camera is case and point. The Z5 Premium adorns a brand new 23 megapixel camera fluent in 4K video recording. Autofocusing happens in 0.03 seconds, and although digital imaging stabilisation is used when recording videos, it’s incredibly effective at ironing out bumps.

This is the same camera found in Z5 and the Z5 Compact and it can compete against the best from Samsung and Apple, only unlike those phones, it doesn’t deface the smartphone’s design because it rests flush on its back.

Sony’s take on the camera is divisive. Take a photo using any smartphone in the Z5 range and it’ll capture the scene as it is. Dark scenes are not artificially lightened, whereas some rivals, think the LG G4 and iPhone 6s, will manipulate photos to make them picturesque. The difference between the resulting photos is noticeable. Neither is technically better than the other; it all boils down to individual taste.

Powering the smartphone is a Snapdragon 810 chipset with two quad-core CPUs, one running at 2.0GHz and another at 1.5GHz. Shared between it and an Adreno 430 GPU is 3GB of RAM, while the smartphone’s 32GB of internal storage can be expanded with microSD cards up to 2TB in size.

This configuration is among the most powerful, with 3DMark’s Ice Storm Unlimited benchmarking test awarding a top score of 26,929, which is behind only Apple’s iPhone 6s, and ahead of Samsung’s Galaxy S6 and HTC One (M9).

Read more: Tablet war waged for 12 November by Apple and Microsoft in Australia

The smartphone supports Cat6 LTE networks with a theoretical maximum download speeds of 300Mbps. Popping in a Telstra SIM and running a speedtest in our North Sydney office returned maximum download speeds of 62Mbps and upload speeds of 22Mbps. Downloading a 1-gigabyte file at this rate would take 2 minutes and 18 seconds.

Buying an Xperia branded phone comes with certain guarantees and one of them has to do with its tough credentials. The Z5 Premium has earned IP65/68 ratings, which certify it is resistant to dust and that it can withstand water up to 150cm deep for thirty minutes. These certifications are guidelines; an indication of what Xperia smartphones can do under controlled conditions.

The real value of a water resistant phone is it affords peace of mind. There’s no need to worry about raindrops, spills or wet hands. Wash it clean, dry it up and it’s good to go.

Sony’s Xperia Z5 and Z5 Compact are better smartphones for having water resistant credentials, but the Z5 Premium is not. Sony’s Xperia range has all modelled the same design language since the original Z, launched in 2013, because in order for them to be waterproof, they need to be hermetically sealed.

There’s nothing wrong with the design of the Xperia Z5 Premium other than it is pushing three years old. Good design matters. It is the one thing that allows technology to appeal to human emotions.

This is the first Sony smartphone which Samsung, HTC, LG and Apple are chasing. It is the first smartphone in the world to take young 4K technology and implant it, practically, into a phone. This is Sony’s moment, the company has arrived, and its impact has been discounted by making the Z5 Premium look little different to some of Sony’s cheapest phones.