Brian X. Chen, New York Times:
The iris scanner shines infrared light in your eyes to identify you and unlock the phone. That sounds futuristic, but when you set up the feature, it is laden with disclaimers from Samsung. The caveats include: Iris scanning might not work well if you are wearing glasses or contact lenses; it might not work in direct sunlight; it might not work if there is dirt on the sensor.
I don’t wear glasses or contact lenses and could only get the iris scanner to scan my eyes properly one out of five times I tried it.
When you set up the face scanner, Samsung displays another disclaimer, including a warning that your phone could be unlocked by “someone or something” that looks like you. (Hopefully you don’t have a doppelgänger in the primate kingdom.) In addition, face recognition is less secure than using a passcode. So why would you even use it?
Underscoring that last feature, Edoardo Maggio writes for Business Insider:
Web developer and user experience designer Mel Tajon ran a test with the Note 8, and found its facial recognition feature can be tricked with a photograph.
What’s worse is that even relatively low-quality pictures such as those uploaded on Facebook and Instagram can seemingly do the trick. “Confirmed: I’m also able to unlock the Samsung Galaxy Note 8 with people’s Facebook profile pics and Instagram selfies from my iPhone,” said Tajon.
Facial recognition may be hard, but if it doesn’t really work to reliably authenticate a specific user, why ship it at all?
Update: It has been pointed out to me that Tajon’s experience was with a Galaxy Note 8 in “kiosk” mode, which may not perfectly match the shipping device. I think that’s fair, but I also think it’s fair to consider that there’s a Touch ID demo on iPhones in Apple Stores, and it’s just as reliable as the shipping product. Also, as Chen notes, there is a disclaimer that appears when activating Samsung’s facial recognition feature, noting that similar-looking people could unlock the device. Do you think an iPhone with facial recognition would have a similar warning? I don’t.