The Nexus 5 will be the first smartphone to feature a MEMS camera, allowing for ultra-fast focusing, and Lytro-like focusing where you can refocus a photo after you capture it. Google is expected to officially unveil the Nexus 5 soon. From what we know so far, the Nexus 5 will be made by LG, and it will have a 4.96in 1920 x 1080 screen, a Snapdragon 800 SoC, 2GB of RAM, a 2,300 mAh battery, and all of the usual connectivity for a superphone: LTE, Wi-Fi, NFC, Bluetooth, etc. But let’s talk more about that MEMS camera.
MEMS, or microelectromechanical system, is a phrase that basically describes really, really small machines. There are no fixed rules on how a MEMS works, only that it usually involves very small moving parts – usually fashioned out of silicon, polymer, or ceramics – that are actuated with effects such as piezoelectricity, electrostatics, and wetting.
So you have some idea of the scale, individual components in a MEMS are fractions of a millimetre, and whole devices are generally less than 1mm square. It may help if you simply think of MEMS as one step above nanobots and other nano-scale machines: If we keep up the miniaturisation (which we will), MEMS will eventually turn into nanobots and co.
There are lots of examples of MEMS in current, consumer-level tech. Inkjet printers use piezoelectric MEMS to dispense tiny dots of ink on paper. The gyroscope and other sensors in your smartphone probably use MEMS. And now, it would seem, according to what appears to be a log of the device’s boot process, the Nexus 5 will use the IMX179 MEMS camera module from DigitalOptics.
As far as we can tell, the IMX179 module [PDF] is exactly the same as the DigitalOptics camera that we discussed in our feature entitled Beyond mere megapixels: The smartphone camera of the future.
The unit has a 1/3.2in sensor packing 8-megapixels, an aperture of f/2.4, minimum focusing range of 10cm, and a MEMS-based autofocus system. Traditionally, most lenses are focused with voice coil motors (VCMs), which step through the focus range, evaluating each image to see if it’s in focus. This method, as you’ve probably seen on your smartphone as it tries to find focus, is slow. MEMS is a lot quicker than VCM; DigitalOptics has demoed one of its units taking multiple photos, at different focus distances, in under a second.
We obviously don’t know the exact feature set of the Nexus 5, but we assume that its camera software will have a burst mode that takes advantage of the MEMS autofocus to capture the same scene at different focuses. As you can see in the video above, you will then be able to “refocus” your photo by scrolling through each of the different focuses. This is very different from the light field approach used by Lytro and Pelican, but the end result is essentially the same: You can snap photos without worrying about whether the subject is in focus or not.
It’s worth pointing out that the DigitalOptics module is expensive – $25 (£15) each for orders of 10,000 or more – which is probably the reason that it hasn’t found a home in a smartphone yet, despite being on the market for more than six months. Whether this will affect the price of the Nexus 5, or if Google/LG has done some wheeling and dealing, remains to be seen. The Nexus 5 is expected to be unveiled later this month, which should also be the first time that we see Android 4.4 KitKat. The release date is unknown, but it’s likely to be October or November.