Sony Xperia Z4
The Sony Z3 is about to get an upgrade with the new Xperia Z5Reuters/Toru Hanai

Sony is expected to use its press conference at the IFA technology show in Berlin to announce a whole host of new products. No fewer than three new smartphones are expected to be revealed under the new Xperia Z5 name. You can watch the event unfold live online, after which IBTimes UK will be present in Berlin to provide our hands-on first impressions of what Sony has to show us. The event kicks off at 3pm GMT (4pm local time) today (2 September 2015) and should last for around one hour.

Sony's live stream will appear on its official blog, and if the company also decides to use YouTube, we'll embed that video into this article, below. Thanks to a number of leaks from the online rumour-mongers, we have a pretty clear idea of what to expect. Sony is believed to be showing off three new members of the Xperia family: these are the Z5, the Z5 Compact and the Z5 Premium – also known as the Z5 Ultra. The first two handsets are fairly self explanatory: both are upgrades to the Xperia Z3+ and Z3 Compact.

However, the Z5 Premium is something altogether more interesting, If the rumours and leaks are to be believed, then this will be the world's first 4K smartphone. This means a screen with more than 800 pixels per inch (remember when the iPhone was impressive at 326ppi?) and the ability to record, play and share 4K video. At 5.5in, the screen will be the same size as that of the iPhone 6 Plus, and we're not expecting any major design changes over the last few Xperia Z handsets.

Sony often uses the IFA to reveal new televisions, wearables and other tech, so keep your eyes peeled for those later in the week.