[Disclaimer: I do not work for Nokia, and never have. Despite the fact that the piece of paper says "Nokia Academy" on it, it's simply the only paper I had on hand so I used it as a backdrop.]
The Optical Image Stabilization system in the Lumia 920 is arguably its best selling point. However there seems to be quite a bit of confusing in the tech sphere as to exactly how it works. For example, c|net writes in its product review that the Lumia 920 uses "...springs for stabilizing images...." Traditional image-stabilization techniques are actually a bit more complicated and involve electromagnets and gyroscopes. Sitting in on the Carl Zeiss presentation at #LumiaFactory in Berlin, we were told that the Lumia 920 manages its stabilization magic using microscopic motors.
So... how does the thing actually work? To find out, I decided to dig out the imaging unit from the kit of Lumia 920 pieces that I was sent a while ago, and tear into it. Lacking my set of watchmaking screwdrivers, the only tool I had to work with was my trusty Leatherman multitool, and this caused a few issues... as you'll soon see. It's probably worth mentioning that this thing was sent to me before the Lumia 920 was announced as being officially ready for customers to purchase, so it might vary from the unit found in final, consumer-ready handsets. Anyway... let's dig in.
Above, we've got the unit itself. It's a bit boring.
With a little bit of prying, I managed to get the entire lens assembly off of the circuit board. You can see the electrical contacts line up with matching points on the circuit board. Clearly, there's more than just springs at work here, c|net. Also, as you'll see in a second...
...I sort of made a mess of getting what I assume to be the UV filter separated from the lens assembly. I blame that on the bluntness of the Leatherman. At least this part was boring, so I can simply dump all those tiny glass fragments into the trash.
There you go, the circuit board and imaging sensor. The size of the sensor caught me off guard, especially given the diminutive diameter dimensions of the external-most lens on the lens assembly. Check out the size of the sensor in comparison to the hole that's cut in the metal casing for the entire imaging unit. Definitely a pretty sizable sensor!
Alright, I've now removed the metal shield from around the OIS unit. Some minuscule copper wires are visible at this point. At this point I think it's obvious that there's more to this thing than simple springs, no?
Remove a bit of plastic, and there you have it... copper wires going every which way. Turns out there are a bunch of electromagnets in this thing. My camera was incapable of capturing much better detail than this, but an odd suspension system of springs and some sort of silicon-like rubber is used simply to support the structure and, I assume to dampen movement intensity and prevent excessive degrees of movement.
I've now separated the lens from the "base" electromagnets. Those four metallic rectangles around the lens? Permanent magnets.
Once the permanent magnets are removed, additional electromagnets are exposed. There are at least 8 separate electromagnets in the OIS assembly... impressive, no?
I used the magnifying glass that also came in the parts kit to try and get you a better idea of exactly how minuscule these things are.
And there's the circuit board and the image sensor.
Yeah, the permanent magnets are really strong. This whole array of 'em didn't really want to let go of my Leatherman.
Check out the design of the lens located right before the imaging sensor! Unfortunately I wasn't able to get this sealed assembly apart, but that's alright as here's where the magic ended. This lens' unusual shape really intrigued me, and it's weird to think of how the clear pictures and videos that the 920 is capable of capturing have all traveled through this lens. Physics is crazy!
And that's it! Now you don't need to take your phone apart to figure out how the magic works.