Nokia 808 PureView
Nokia 808 PureView
The Nokia 808 PureView is a Nokia Belle powered smartphone, first unveiled on 27 February 2012 at the Mobile World Congress. It is the first smartphone to feature Nokia’s PureView technology, a pixel oversampling technique that reduces an image taken at full resolution into a lower resolution picture, thus achieving higher definition and light sensitivity, and enables lossless zoom.
It features a 41 megapixel 1/1.2″ sensor and a high resolution f/2.4 Zeiss all-aspherical 1-group lens. The 808’s sensor was the largest and highest resolution sensor in a cameraphone at the time of its launch, a record previously held by Nokia’s N8, sporting a sensor 2.5 times larger than that of its predecessor.
The 808 won the award for “Best New Mobile Handset, Device or Tablet” at Mobile World Congress 2012, and the award for Best Imaging Innovation for 2012 from the Technical Image Press Association.
PureView Pro sensor has an active area of 7728 x 5368 pixels, totalling over 41Mpix. Depending on the aspect ratio chosen by the user, it will use 7728 x 4354 pixels for 16:9 images/videos, or 7152 x 5368 pixels for 4:3 images/videos. What happens next depends on the settings and whether or not zoom is used. But to give an idea, the default still image setting is 5Mpix at 16:9, and for video, 1080p at 30fps. Using these settings, the zoom is around 3x for stills and 4x for video. Conventional digital zoom tends to scale up images from a relatively low resolution, resulting in poor image quality.
The image sensor is capable not only of delivering parts of its pixels, but of down- or oversampling its resolution by having its own on-chip image processor, highly reducing external processing needs and data rates as well as image noise (see noise shaping) when lower resolutions (or HD video) are needed. Additionally this provides very high image resolution. Images up to 38 megapixels can be taken at full resolution at 4:3 aspect ratio and 34 megapixels at 16:9 ratio.
PureView Technology [PDF]: Nokia PureView Imaging Technology