Fingerprint Sensor - Helpfull Tips
I've been playing around with the fingerprint sensor just to get a feel on how it works and have stored at least a dozen different prints into it (yes, it only stores five at a time, but you can make room by deleting old ones). The fingerprint stored is not the "whole fingerprint" as in those scanners you can see with police, immigration or customs. Instead the fingerprint stored is actually a mathematical "code" the Touch ID calculates while you are teaching the new fingerprint to it. And this leads to several things:
1) The button does not have to be pushed for the sensor to work. In fact it works a lot better when you don't apply pressure.
2) If you are pressing the very same spot of the finger to the sensor then the "code" is calculated using the lines on that spot only. This is good and bad. It means if you teach the sensor, for example, the tip of your thumbs then the sensor will, quite consistently work correctly as long as you use the tips of your thumbs. However, it will NOT work correctly if you are using any other part of the thumb.
3) If you are more, let say "liberal", with you application of the fingerprint when teaching the sensor the "code" will be calculated using a wider set of lines. This is also good and bad. This means you don't have to be so consistent on how and what part of the finger you are using but it also means a bigger failure rate. Which might explain why some people have the sensor work only part of the time. At least I've noticed that the more exact work I do when teaching the print, the better it works... as long as I remember which part of the finger I was supposed to be used.
4) And this if VERY interesting... It can store other prints too. Yep. I've successfully teached the fingerprint scanner to use my thumb joints and the edge of the hand where pinky finger starts. I've opened my phone several times using both, so I know it works and I'm sure you can use ANY part of the palm as your "fingerprint" if you just do it right. Haven't tried coding the tip of my nose yet, but it just might work, too