Nokia 808 PureView

Nokia 808 PureView Mobile Phone Features:

• 3G
• Wi-Fi
• 41 MP Camera
• Nokia Belle OS
• 1080p HD Video
• Full Touchacreen
• Social Networking

Nokia 808 PureView Phone Technical Details: Network:

• GSM/EDGE 850/900/1800/1900 MHz
• WCDMA 850/900/1700/1900/2100 MHz
• 3G Speed: Up to 14.4 Mbps, HSUPA Up to 5.76 Mbps

Platform:

• Nokia Belle Operating System

Processor:

• 1.3GHz Processor
• Dedicated Graphics Processor with Open GL 2.0 Enables 3D Graphics

Connectivity:

• Wi-Fi
• HDMI Support
• DLNA Support
• Secure NFC
• Bluetooth v3.0
• Micro USB v2.0
• 3.5 mm Nokia Standard Audio Connector with TV-Out

Battery Life:

• Talk Time: 2G Up to 11 Hours, 3G Up to 6.5 Hours
• Standby Time: 2G Up to 465 Hours, 3G Up to 540 Hours

Audio/Video Features:

• Stereo FM radio
• Multi Format Audio Player: MP3, M4A, AAC, AAC+, eAAC+, WMA
• Multi Format Video Player: H.264, MPEG-4, VC-1, Flash Lite 4, On2 VP6, Sorenson Spark
• Ringtones: mp3, AAC, eAAC, eAAC+, WMA, AMR-NB, AMR-WB Ringtones

Display Screen:

• 4.0″ Inch ClearBlack AMOLED (640 x 360) Pixels Capacitive Touchscreen

Camera:

• 41 Megapixels Camera
• Highest Performance Carl Zeiss Optics
• 1080p HD Video Recording @ 30 fps

Design & Build:

• Touchscreen Bar

Sensors:

• Digital Compass
• Accelerometer
• Proximity Sensor
• A-GPS with Google Maps

Memory:

• 16GB Internal Storage
• Expandable Up to 48GB

Pre-Loaded Apps & Messaging:

• Social Networking: Facebook, Twitter
• Email: Yahoo! Mail, Gmail, Windows Live, Hotmail And Other Popular POP/IMAP Services, Mail for Exchange
• Messengers: Gtalk, Yahoo, Live

Others:

• Detailed Contact Information
• Multiple Calendars with Meeting Request Support
• To-do list
• Notes
• Recorder
• Calculator
• Clock

Dimensions & Weight:

• 123.9 x 60.2 x 13.9 mm
• 169 gm
• Volume: 95.5 cc

 

The Nokia 808 PureView is a Symbian Belle powered smartphone, first unveiled on 27 February 2012 at the Mobile World Congress. It is the first smartphone to feature Nokia's PureView imaging technology based on a new 41 megapixel oversampling 1/1.2" sensor and a high resolution f/2.4 Zeiss all-aspherical 1-group lens. See examples.
The 808 won the award for "Best New Mobile Handset, Device or Tablet" at Mobile World Congress 2012.

PureView Pro is an imaging technology used in the Nokia 808 PureView device. It is the combination of a 1/1.2" large, very high resolution 41Mpix with high performance Carl Zeiss optics. The large sensor enables pixel oversampling, which means the combination of many pixels into one perfect pixel. PureView imaging technology delivers high image quality, lossless zoom, and improved low light performance (see below). It dispenses with the usual scaling/interpolation model of digital zoom used in virtually all smartphones, as well as optical zoom used in most digital cameras, where a series of lens elements moves back and forth to vary the magnification and field of view. Instead, it will give around 3x lossless zoom for stills, and 4x zoom in full HD 1080p, for 720p HD video, 6x lossless zoom and for nHD (640x360) video, 12x zoom.
  

Resolution processing image sensor

PureView Pro sensor has an active area of 7728 x 5368 pixels, totaling 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 a new resolution processing image sensor, which 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. The PureView is a pixel oversampling technology used by Nokia that converts an image taken at full resolution into 3, 5 or 8 megapixels to eliminate noise in the image.

Zeiss 1-group lens

The optic is a 1-group lens, which is based on a shiftable fixed-focus lens: identical to the highly regarded prime lenses in most Zeiss Planar or Tessar optics, focus is achieved by varying the distance to the image sensor (unit focusing lens). This construction has the advantage that no movable focus group is needed. Considerable movable (focus-range) lens groups need a minimum of one additional adaptive lens element in both the moved group and the stationary group, increasing the number of elements by at least two. This increases unwanted reflections as well as overall tolerances and therefore decreases sharpness.

Any 1-group lens is additionally an aperture-less lens, further increasing the freedom of lens element arrangement and allowing the designer to optimize the lens to only one f-stop. The lens consists of only 1 group with molded elements, which gives a highly stable, precise mechanical alignment. The lenses are partly made of plastic, which provides sufficient stability at this size and as a 1-group lens and has the significant advantage of making it possible to use extreme aspheric shaped lens elements.[5]

5 all-aspherical lens elements are used, making it possible to increase border-sharpness and lower distortion and astigmatism. The high refractive index, low-dispersion glass additionally helps reduce chromatic aberrations. The disadvantage of a 1-group lens is that no aperture is possible; a neutral density filter with approximately ND8 (3 f-stops) is instead used. Although the lens is named a Vario-Tessar, it has almost nothing in common with the 4 element in 3 group, non-aspherical original Tessar.

Due to the comparatively large image sensor format of 1/1.2" and the comparatively fast lens with f/2.4, the camera has a quite shallow depth of field of approximately f/8, equivalent to a 35mm full-frame or approximately f/5, equivalent to a APS-C DSLR with the same angle of view (without zoom).

Zoom

Zoom with the PureView Pro works in a manner only partly related to the digital zoom principle. With no zoom, the full area of the sensor corresponding to the aspect ratio is used. Although it is only possible in this case to use the full resolution, pixel oversampling can be used to combine many pixels to calculate a single pixel and reduce image resolution. This will filter away visual noise from the image and greatly reduce noise in low-light conditions.

The limit of the zoom is reached when the selected output resolution becomes the same as the input resolution. That means once the area of the sensor reaches 3072 x 1728, the zoom limit is reached. So the zoom is always provides the true image resolution the user wants. The level of pixel oversampling is highest when zoom is not used. It gradually decreases until the maximum zoom is hit, where there is no oversampling. At this stage, PureView Pro optics and pixels start behaving in a more conventional way. But because only the center of the optics is used, the best optical performance is achieved – including low distortion, no vignetting and highest levels of resolved detail.

 Autofocus

PureView Pro comes with improved autofocus also for video as the optics with the larger image sensor provide a relatively shallow depth of field. PureView Pro gives continuous auto focus in all shooting modes, close-up (Macro) focus, Face detection, Touch focus with easy manually selected focus point and Hyperfocal distance focus for defined depth of field, for extreme focus speed or when no reliable focus is possible due to darkness.

 Video

Most smartphone manufacturers crop off a section of the sensor to ease the processing load. In contrast, the on-chip oversampling image processor of PureView Pro enables oversampling of all 38Mega-pixels even at the high data rates of 1080p with 30 fps. Plus, it provides lossless zooming capability, which is output resolution dependent. Full HD 1080p gives 4x zoom; 720p HD video, 6x lossless zoom; and for nHD (640x360) video, 12x zoom. In addition, encoding is up to 25Mbps in 1080p H.264/MPEG-4 HD video format. The PureView Pro sensor integrates a special video processor that handles pixel scaling before sending the required number to the main image processor.