You've probably heard of Carl Zeiss -- even if you're not a photography junkie or even own a DSLR; they are a world class lens manufacturer for high-end cameras. For example, Carl Zeiss makes lenses for every single high-end professional Sony camera.
Another place you might have heard of them is on Nokia's PureView Windows Phone devices. Carl Zeiss lenses in phones doesn't seem so farfetched, but before this it was hard to associate a company that makes lenses bigger than your hand making something that could fit in your phone -- but that is exactly what happened.
A Nokia interview shows that Carl Zeiss was interested in the mobile market before there were even cameras on phones that you'd consider using instead of a point-and-shoot. They internally decided that they wanted to wait for a camera to have at least two megapixels! They decided on this because two megapixels is where they found a good optical system to have a difference on image quality.
In 2004, they believed that their target pixel quantity was going to be met and did studies on the different phone OEMs to find a suitable match. By the end of 2004 they were talking to Nokia and had found a common understanding of the future of mobile imaging. In three months they went froman initial contact to a signed contract.
Nokia and Zeiss engineers first started the collaboration with a week of team-building and then had meetings at least twice a year in addition to weekly teleconferences and emails. This decade of collaboration has resulted in Windows Phone devices with cameras in an entirely different class than the competition.
One of the biggest challenges the two teams faced was the size, and more specifically, the height, of the camera. If you've seen a Lumia 1020, with its 41 megapixel beast of a camera, you will remember the bump on the back that is needed to house the camera module. However, they worked on putting similar quality in slimmer phones, and you can see the rewards in the 1520 and 930 which both have 20 megapixel cameras. The 830, with its relatively conservative 10 megapixel camera was made possible by a unique optical design that made the lens thinner.
In the future Zeiss expects the limit to be around five to six millimeters for camera modules while retaining quality. However, they are exploring new technologies that promise even thinner devices further in the future. And if someone can, its the company with the foresight to see the future of mobile before 2004.
You can read the full interview in the source below.