Most of us expected a form of 'phase 1', i.e. large sensor and pixel oversampling, to be implemented on Windows Phone and I guess the compromises in terms of form factor were just too severe for these new Windows Phone designs, which is why Nokia turned for these designs to 'phase 2', also from their labs.
The best way to explain PureView phase 2 is to quote from my piece over on AAWP:
Seeing the PureView label on the new Nokia 920 will instantly draw comparisons with Nokia's 808 PureView running Symbian, which used a massive 1/1.2" sensor and 41 megapixel array to do stunning 'software photography', with noise-reducing pixel oversampling and lossless zoom options. However, in truth there is no comparison, since 'PureView' in the Lumia 920 is totally and utterly different. The camera in this device does bring potentially big improvements for the typical/traditional 1/3" sensor phone camera, but it works in a totally different way. Read on for more...
My first reaction was to wonder what the guys who thought up the oversampling/zooming system in the first place might think of the use of the 'PureView' label for the Lumia 920's 8 megapixel camera, but at the end of the day it's Nokia's imaging 'brand' name and if the company wants to apply it to other camera-improving technologies then that's of course their absolute perogative.
Unlike the 808's use of a large sensor to improve photos, the Carl Zeiss-lensed Lumia 920 has:
- a "floating lens" optical image stabilization system for "much sharper photography in low-light situations".
- a F2.0 aperture
- BackSide Illuminated (BSI) 8.7 Megapixel sensor
- an improved camera interface
- the ability to record 1080p HD video
- a "next generation short pulse high power" LED flash
Taking each of these points in turn...
Don't be fooled that this is a traditional Optical stabilisation system though - in standalone cameras, the lens is the only thing that moves. With the smaller mass of components in a phone, Nokia has been able to implement a (presumably) piezo-driven mounting for the entire Lumia 920 optical assembly (i.e. lens and sensor). With closed loop electronics and gyroscope input, the assembly is then moved to compensate for small movements made by the user, up to 500 times a second.
For still photos, it means less images ruined by 'camera shake' and it means better* low light photos since longer shutter times can be used, with the images less subject to the phone being moved by the user inadvertently.
I wouldn't rule out a hybrid device (running Windows Phone, no doubt) with both 'phase 1' (perhaps 21MP base sensor) and 'phase 2' (optical stabilisation) popping up in 2013. Now that might be rather exciting for camera phone fans....