Face ID vs Touch ID

Apple's new method for unlocking the iPhone X, called Face ID, certainly raised some eyebrows. Is it secure? Is it necessary? And is really going to be as convenient, if not more so, than unlocking the phone with your fingerprint? 

This is perhaps the stickiest sticking point: Touch ID has a proven ability to quickly and conveniently unlock the phone. With the home button completely gone on Apple's most premium phone, you'll be completely reliant on Face ID. Apple thinks you won't miss it one bit. 

I haven't yet had a chance to try Face ID, so I don't know every nuance of Apple's creation, and even at the iPhone X launch event, the closest we ever came was Apple staff demonstrating the feature. 

Apple's Face ID may be untested, but I have extensively tested unlocking mechanisms that use your face, from the Lumia 950's iris unlocking to Samsung phones' iris scanning and facial recognition (which scans your face Galaxy S8, Galaxy S8 Plus and Galaxy Note 8.

Here are the problems that repeatedly come up: compared to using a really good fingerprint reader, iris scanning of the past hasn't always been as accurate, speedy or dependable. Those concerns naturally spill over to Face ID. And with just a passcode pin as your backup, any time Face ID fails is a time you're punching in that pin.

Of course, we'll give Face ID a fair shake when the iPhone X comes out -- it might convince us that face scanning is the best thing since, well, since Touch ID. And when we do finally go eye-to-eye with Face ID, here's are the five things we'll be paying attention to.

1. Face ID must be easy to trigger, and easy on the arms

Where I hold a phone and scan a phone are about 11 inches apart. Your delta may vary based on your height.

Patrick Holland/CNET

If you're like me, you keep your phone nearby pretty much all the time, often lying face-up on some sort of surface, like a table or desk. The current set of iPhones -- and even the newly-announced iPhone 8 and 8 Plus -- will unlock easily with your thumb, without you having to do much lifting. 

If you take any other phone with a home button out of your pocket or purse, you can pretty much unlock it by the time you're ready to read the screen. That goes double for recent iPhones with Touch ID 2, which is lightning fast.

On the phones I've tested with iris scanning, that stops being the case the second you unlock it with your face. Unless you're leaning over it, until your eyes hit the target, you wind up raising it higher than you would normally hold your phone (exception: when you're taking a photo), just to bring it back down again. 

A coworker helped me measure the distance between where I comfortably hold the Galaxy S8 and where I hold the Galaxy Note 8 to use iris unlock (both phones have it, by the way). It was about an 11-inch difference, give or take

How many times do you unlock your phone in a day? A dozen? More? How about in a week? Imagine lifting the phone each time to do so, imagine all that wasted movement. 

Apple's SVP of software, Craig Federighi, noted to Tech Crunch that you can also angle the phone to fit in your eye, nose and mouth, the three elements Face ID needs to work. The video Apple used to explain Face ID suggests that the feature is forgiving, that you'll barely have to position yourself to make it work at all. If that's true, it'll go a long way to making Face ID a convincing Touch ID alternative. If not, get ready for some pissed-off people.

2. Face ID will have to be fast and accurate

Iris scanning is almost instantaneous when it works the first time, but even if Face ID is just as rapid or even faster, it still takes longer to lift your arm up and bring it back down again than it does to press your thumb on a device that's already in your hand.

Face ID's additional challenge is that the second generation of Touch ID (which launched on the iPhone 6S) is so quick and convenient, you hardly know it's there. But even if Face ID is perfectly fast and reliably works every time, it essentially turns Touch ID's one-step unlocking process into as many as three steps. 

With Touch ID, touching fingerprint sensor simultaneously:

Wakes the iPhone
Unlocks the iPhone
Gets phone to home screen (if you disable the default "click to unlock" setting)

...all in a fraction of a second.

With Face ID, you seem to have to:

Wake the iPhone by raising it or tapping the screen
Position the phone (or you) so it can scan your face
Swipe to get to the home screen after you unlock the phone (it appears to unlock to the notifications shade)

Why so many steps? Because the phone isn't always watching you, presumably to save battery life. It'd be wonderful if the iPhone X has an option or you to unlock straight to the home screen or the last app you used, if that's how you prefer it.

Apple didn't respond to a request for clarification on that issue.

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