Hands on with Sony’s new Xperia Z5 phones, including that ludicrous 4K display

BERLIN—Forget QuadHD displays: the new hotness is 4K. At IFA 2015, Sony took the wraps off its new Z5, Z5 Compact, and Z5 Premium phones, with the flagship Z5 Premium sporting a 5.5-inch 4K (3840×2160) display, which works out to a ridiculous 806 PPI. The jury's still out on whether you actually need a 4K display in a phone, but—in Sony's demos, at least—it looked ridiculously good, with vibrant colours and deep blacks.

4K content is still thin on the ground, though, and while Netflix's Android app does support 4K, it only does so for a limited number of devices—it's not clear yet whether the Z5 Premium is one of them. There's also the worry of how much of an effect that 4K screen will have on battery life. Sony's Xperia series has historically had great battery life (up to two days in the case of the Z3 Compact), so it'd be a shame to see that disappear because of a crazy high-resolution screen. For its part, Sony says the Z5 Premium's beefy 3430mAh battery will be good enough for two days of use.

Aside from a 4K display, the Z5 Premium also features a blingtastic mirrored glass back in black, gold, or chrome. No doubt it will need constant cleaning to keep it looking shiny. Sadly, while we didn't get any hands-on time with the Z5 Premium, we did get to play with the Premium's little brothers. Aside from the 4K display and glossy finish on the Premium, all of the Z5 smartphones have near-identical specs.

On the normal Z5, there's a 5.2-inch IPS 1080p display; on the Z5 Compact, it's a 4.6-inch 1280×720 IPS display. All phones continue Sony's "OmniBalance" design theme, which has been around since the Xperia Z1. That means you're looking at uncomplicated rectangular slabs, with minimal (read: unnecessary) design flourishes. The Z5 series is the most accomplished take on the formula yet, though, and they look fabulous in the flesh. The stereo speaker grilles on the front of the phone have been slimmed down, while the metal banding around the outside has a brushed aluminium finish that feels great in the hand.

The best change, though, has happened on the rear of the phone, with the standard glass finish of the Z3 series replaced with frosted glass. Personally, I think the Z3 Compact is the best Android phone ever made (it's still my daily driver to this day), but I have to admit that the glass back has always been a pet peeve, sometimes making the phone far too slippery. I'm pleased to say the frosted glass of the Z5 is a vast improvement—not to mention it feels more expensive, too.

Hardware-wise, all phones sport the same Qualcomm Snapdragon 810 processor, up to 32GB of storage (expandable via micro SD), as-yet-unnamed "high-res audio" chips, two-day battery life, and a fingerprint sensor built into the power button on the right edge of the phone. While the Premium is equipped with a hefty 3430mAh battery, the Z5 and Z5 Compact make do with 2900mAh and 2700mAh batteries respectively. The only other difference is with RAM: The Z5 Premium and Z5 have 3GB, while the Z5 Compact has 2GB.

Given that Sony makes image sensors for a lot of big smartphone companies (yes, even that one), you'd hope that it could make a decent camera for its own phones. While the Z3 series took pretty good snaps, Sony's hoping the new 1/2.3-inch Exmor RS 23-megapixel image sensor—which is exclusive to Xperia phones for the moment—does the trick. The new sensor is backside illuminated for better low light performance, and has embedded phase-detection pixels for autofocus as quick as 0.03 seconds. There's a new six-element 24mm lens with a wide f/2.0 aperture, too, which should make for some nice depth of field effects. All Z5 phones support recording 4K video.

Software wise, the Z5 family runs Android 5.1.1, and Sony says there's likely going to be an Android M update on the way too. Most importantly, Sony is finally ditching most of its custom skinning, instead opting for a mostly stock Android experience. The few non-stock tweaks come from baking in fingerprint support, something which isn't officially coming to Android until the release of M. Unfortunately, I wasn't able to test the fingerprint functionality in my brief hands-on, but the scanner's position on the side of the phone felt more natural than having it on the back or down at the bottom.

While the Z5 Premium comes in black, gold, or chrome, the Z5 and Z5 Compact are available in a few snazzier colours: white, black, gold, and green for the Z5, and white, black, yellow, and pink for the Compact. Like their predecessors, all Z5 phones are rated IP68 (dust and waterproof), and the slightly irritating flap over USB port has been removed, meaning the only flap you have to deal with is the one over the SIM card and micro SD card slot (which you won't be opening very often anyway). There's also support for quick charging with a Quick Charge 2.0 charger, which promises 5.5 hours of use with just 10 minutes of charging.

While they're perhaps not the most eye-catching phones around, the Z5 line-up is hugely impressive, mostly because they're just so darn practical. If the camera lives up to the hype, then they'll take great photos; if their battery life is as good Sony says it is (and I've no reason to doubt it given I've gotten two days out of my Z3 Compact before), then you won't need to worry about being away from a power socket; and if the phone accidentally ends up down a toilet or in the sink on a drunken night out, it won't die.

The Z5 and Z5 Compact will be available globally this October, with the Z5 Premium following in November. Pricing is yet to be confirmed, but we'd expect the pricing to be in-line with the iPhone: so, about £550 (€700) for the Z5 and £650 (€800) for the Z5 Premium. The Z5 Compact will hopefully be around £450.