This story has been updated with hands-on video.
What if, instead of using your fingerprint to unlock your phone, you just looked at it?
This is one tool that Microsoft brings to its Lumia 950 and larger Lumia 950 XL as Microsoft's first Windows 10 phones. Even without biometric iris-scanning, the duo makes a strong showing for Microsoft. They have big, sharp displays, proven processors, a cutting-edge USB Type-C charging port and two things a lot of buyers cherish: a removable battery and a microSD card slot for extra storage.
Plus, there's a 20-megapixel camera to lure shutterbugs and some handy tie-ins to the wider Windows 10 world, including the ability to use apps originally made for the laptop and tablet, and to pick up on one device where you left off on another.
On paper at least, the Lumia 950 set is off to a good start, but since it still drags far behind Google's Android and Apple's iOS platforms, Microsoft's simpler phone software has to prove itself to buyers.
Despite peppering markets with midrange and "value" Lumias, it's been over a year since the last high-end flagship. Together, Android and iOS gobble up nearly all the worldwide marketshare, though Microsoft's low-cost Lumia strategy has gained it a larger following in some regions, like Russia, than in others, like the US. (Here's a handy interactive map from Kantar Worldpanel that helps visualize Microsoft's global impact.)
This is not Microsoft's first time betting it all, but its Windows 10 Lumia phones enters the phone scene alongside a slew of compelling rivals, from direct-to-consumer offerings to totally new crowd-funded entrants.
The Lumia 950 and 950 XL share most core specs below, though the XL has the larger screen and battery, and a different processor with eight cores rather than six.
Unlike a lot of flagship phones today, they're both made of plastic, not metal. The don't look or feel as premium, but they also won't pile up with fingerprints. Straight sides make them easy enough to grip and handle.
The three power and lock buttons on the right spine are metal, though, as is the dedicated camera button along further along the side. I like these a lot, both to trigger the camera and to take the picture. Other competitors are starting to add their own quick-launch camera functions, like double-tapping the home button. Regardless, I'm happy to see this here.
Fingerprint readers are having a moment, but you won't find one on either new Lumia 950 phone. Instead, there's Windows Hello, which uses biometric data to authorize your login in the form of iris recognition. After registering your eye, the phone's front-facing camera is able to detect your unique characteristics from others.
It all happens through a processor that Microsoft has licensed from chipmaker Intel, and a depth-sensing camera that relies on infrared cameras to identify your features.
Windows Hello will launch on the Lumias in beta, but will work right out of the box. As long as the phone is close enough to your face, it happens quickly. It emits a red light when it's sensing, then, once the phone recognizes you, it flashes your name up top -- "Hello, Jessica" -- and then you're in.
A phone adaptation, Windows 10 on phones includes some menu toolbars within Universal apps (like Word) that pop up on the bottom of the screen rather than the top. You can also press and hold on the Windows start button to condense the screen toward the bottom, so your fingers don't have to reach as far if you're using the device one-handed.
Microsoft sees its Lumia smartphones as part of a wider system that also links to your Windows 10 laptop and tablet. On the phone, you'll be able to use many of the same apps that were purposely built for those larger-screen devices. Will this capability, called Universal Apps, be enough access to programs to silence detractors that pick at a smaller catalog of hit apps available on Windows phones? The world's largest software company sure hopes so. (Check out our hands-on with Universal Apps here .)
Further linking phones into the Windows 10 worlds is something called Continuum for Phones, which essentially morphs your phone into a PC experience. So say you take the Lumia 950 on a work trip. You can connect it to a larger monitor, a keyboard and a mouse and work on a "universal" Office app, like Word, without offloading any of that saved work from your phone. Whatever you see on the phone adapts to fill the larger display.
You can do this wirelessly, using Miracast, or through the Microsoft Display Dock, a rather heavy after-market accessory that provides the TV or monitor connection (via an HDMI or DisplayPort connection) and three USB ports for adding accessories. Miracast will be the more convenient approach, but performance won't look as smooth as it will if you use the Display Dock, at least according to Microsoft.
The Lumia 950 will be available in November starting at $549, which directly converts to about £360 and $AU768. In Australia, Microsoft has said the handset will be on sale "before Christmas".
See all of today's Microsoft news.