The Nokia 808 PureView is a Symbian-powered

smartphone A smartphone is a portable computer device that combines mobile telephone and computing functions into one unit. They are distinguished from feature phones by their stronger hardware capabilities and extensive mobile operating systems, whic ...

first unveiled on 27 February 2012 at the Mobile World Congress. It is the first smartphone to feature Nokia's

PureView Nokia PureView is the branding of a combination of technologies used in cameras of Nokia-branded smartphones, and previously, in phones by Microsoft Mobile. PureView was first introduced with Nokia 808 PureView. Hardware PureView cameras have ...

Pro technology, a pixel

oversampling In signal processing, oversampling is the process of sampling a signal at a sampling frequency significantly higher than the Nyquist rate. Theoretically, a bandwidth-limited signal can be perfectly reconstructed if sampled at the Nyquist rate o ...

technique that reduces an image taken at full resolution into a lower resolution picture, thus achieving higher definition and light sensitivity, and enables lossless

digital zoom Digital zoom is a method of decreasing the precise angle of view of a digital photograph or video image. It is accomplished by cropping an image down to an area with the same aspect ratio as the original, and scaling the image up to the dimen ...

. It was one of the most advanced camera phones at the time of its release in May 2012. The Nokia 808 features a 41 MP 1/1.2 in (10.67 × 8 mm) sensor and a high-resolution f/2.4 Zeiss all- aspherical 1-group lens. The 808's sensor was the largest (over 4 times larger than typical compact cameras) sensor ever to be used in a cameraphone at the time of its launch, a record previously held by Nokia's N8 and, as of September 2014, by the Panasonic Lumix CM1. The resolution of the sensor remained the highest to be used in a cameraphone until January 2019, when the Honor View 20 was released with a 48 MP sensor. 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 The Technical Image Press Association (TIPA)Technical Image Press Association
is an international,

. It was also given a Gold Award by Digital Photography Review. On 24 January 2013, Nokia officially confirmed the 808 Pureview to be the last Symbian smartphone. In July 2013, Nokia released the

Lumia 1020 The Nokia Lumia 1020 (known as Lumia 909 during development) is a smartphone developed by Nokia, first unveiled on 11 July 2013 at a Nokia event in New York. It runs Windows Phone 8, but is also Windows Phone 8.1 ready. It contains Nokia's Pure ...

, a successor running the

Windows Phone Windows Phone (WP) is a discontinued family of mobile operating systems developed by Microsoft for smartphones as the replacement successor to Windows Mobile and Zune. Windows Phone featured a new user interface derived from the Metro design l ...

operating system common to Nokia's newer products.

PureView Pro camera

''PureView Pro'' is an imaging technology used in the Nokia 808 PureView device. It is the combination of a large 1/1.2 in, very high-resolution 41 MP

image sensor An image sensor or imager is a sensor that detects and conveys information used to make an image. It does so by converting the variable attenuation of light waves (as they pass through or reflect off objects) into signals, small bursts of c ...

with high-performance Carl Zeiss optics. The large sensor enables pixel oversampling, which means the combination of many sensor pixels into one image 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 commonly used in other 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. In both video and stills, this technique provides greater zoom levels as the output picture size reduces.

Image sensor

The Nokia 808 has a 41.3

megapixel In digital imaging, a pixel (abbreviated px), pel, or picture element is the smallest addressable element in a raster image, or the smallest point in an all points addressable display device. In most digital display devices, pixels are the sm ...

1/1.2 in CMOS FSI

with 7728x5368

pixel In digital imaging, a pixel (abbreviated px), pel, or picture element is the smallest addressable element in a raster image, or the smallest point in an all points addressable display device. In most digital display devices, pixels are the ...

s. Pixel size is 1.4 µm; sensor size is 10.67 × 8.00 mm. Depending on the aspect ratio chosen by the user, the sensor will use either 7728x4354 pixels (33.6 MP) for 16:9 images, or 7152x5368 pixels (38.4 MP) for 4:3 images when using the default camera software, although third-party apps exist that can capture the full resolution of the sensor. The output from the sensor is processed using the on-

chip Chromatin immunoprecipitation (ChIP) is a type of immunoprecipitation experimental technique used to investigate the interaction between proteins and DNA in the cell. It aims to determine whether specific proteins are associated with specific genom ...

image processor An image processor, also known as an image processing engine, image processing unit (IPU), or image signal processor (ISP), is a type of media processor or specialized digital signal processor (DSP) used for image processing, in digital cameras ...

, resulting in a lower-resolution image with pixel oversampling, lossless digital zoom, or a combination of both. The image processor highly reduces external processing needs and data rates as well as

image noise Image noise is random variation of brightness or color information in images, and is usually an aspect of electronic noise. It can be produced by the image sensor and circuitry of a scanner or digital camera. Image noise can also originate in ...

(see

noise shaping Noise shaping is a technique typically used in digital audio, image, and video processing, usually in combination with dithering, as part of the process of quantization or bit-depth reduction of a digital signal. Its purpose is to increase the ap ...

). At default settings, maximum zoom is 3x for stills (5 MP in a 16:9 aspect ratio) and 4x for video (1080p).

Zoom

Zoom is digital but retains a high resolution due to the 41 MP sensor. 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 3072x1728, the zoom limit is reached. So the zoom 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 centre of the optics is used, the best optical performance is achieved – including low distortion, no vignetting and highest levels of resolved detail. This also means that at full digital zoom, the noise reduction achieved by oversampling (pixel binning) is lost as no oversampling happens at full zoom.

Autofocus

PureView Pro features continuous autofocus in all shooting modes, close-up (Macro) focus,

face detection Face detection is a computer technology being used in a variety of applications that identifies human faces in digital images. Face detection also refers to the psychological process by which humans locate and attend to faces in a visual scene. ...

, touch focus with easy manually selected focus point and

hyperfocal distance In optics and photography, hyperfocal distance is a distance beyond which all objects can be brought into an "acceptable" focus. As the hyperfocal distance is the focus distance giving the maximum depth of field, it is the most desirable dista ...

focus for defined depth of field, for extreme focus speed or when reliably achieving focus is not possible.

Video

The on-chip oversampling image processor of the 808 enables oversampling of all 38 megapixels even at the high video data rates of

1080p 1080p (1920×1080 progressively displayed pixels; also known as Full HD or FHD, and BT.709) is a set of HDTV high-definition video modes characterized by 1,920 pixels displayed across the screen horizontally and 1,080 pixels down the screen ve ...

with 30 fps. Maximum possible zoom is 4x for 1080p, 6x for

720p 720p (1280×720 px; also called HD ready, standard HD or just HD) is a progressive HDTV signal format with 720 horizontal lines/1280 columns and an aspect ratio (AR) of 16:9, normally known as widescreen HDTV (1.78:1). All major HDTV broadcast ...

HD and 12x for nHD (640x360) video. In addition, encoding is up to 25

Mbps In telecommunications, data-transfer rate is the average number of bits (bitrate), characters or symbols ( baudrate), or data blocks per unit time passing through a communication link in a data-transmission system. Common data rate units are mult ...

in 1080p H.264/MPEG-4

HD video High-definition video (HD video) is video of higher resolution and quality than standard-definition. While there is no standardized meaning for ''high-definition'', generally any video image with considerably more than 480 vertical scan lines (N ...

format. The PureView Pro sensor integrates a special

video processor In electronics engineering, video processing is a particular case of signal processing, in particular image processing, which often employs video filters and where the input and output signals are video files or video streams. Video processing te ...

that handles pixel scaling at up to 1 billion pixels per second before sending the required number to the main image processor.

Lens

The 808 has

Carl Zeiss Carl Zeiss (; 11 September 1816 – 3 December 1888) was a German scientific instrument maker, optician and businessman. In 1846 he founded his workshop, which is still in business as Carl Zeiss AG. Zeiss gathered a group of gifted practica ...

5-element lens with f/2.4 aperture and 8.02 mm focal length (35 mm equivalent focal length is 26 mm in 16:9 and 28 mm in 4:3 aspect ratio). Focus range is from 15 cm to infinity (throughout the zoom range). The optics are based on a shiftable

fixed-focus lens A photographic lens for which the focus is not adjustable is called a fixed-focus lens or sometimes focus-free. The focus is set at the time of lens design, and remains fixed. It is usually set to the hyperfocal distance, so that the depth of fie ...

; similar to the

prime lens In film and photography, a prime lens is a fixed focal length photographic lens (as opposed to a zoom lens), typically with a maximum aperture from f2.8 to f1.2. The term can also mean the primary lens in a combination lens system. Confusion be ...

es in most

Zeiss Planar The Zeiss Planar is a photographic lens designed by Paul Rudolph at Carl Zeiss in 1896. Rudolph's original was a six-element symmetrical design. While very sharp, early versions of the lens suffered from flare due to its many air-to-glass surf ...

Tessar The Tessar is a photographic lens design conceived by the German physicist Paul Rudolph in 1902 while he worked at the Zeiss optical company and patented by Zeiss in Germany; the lens type is usually known as the Zeiss Tessar. A Tessar comp ...

optics,

focus Focus, or its plural form foci may refer to: Arts * Focus or Focus Festival, former name of the Adelaide Fringe arts festival in South Australia Film *''Focus'', a 1962 TV film starring James Whitmore * ''Focus'' (2001 film), a 2001 film based ...

is achieved by varying the distance to the

( 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. 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 all-

aspherical lens An aspheric lens or asphere (often labeled ''ASPH'' on eye pieces) is a lens whose surface profiles are not portions of a sphere or cylinder. In photography, a lens assembly that includes an aspheric element is often called an aspherical lens. ...

elements are used, making it possible to increase border-sharpness and lower

distortion In signal processing, distortion is the alteration of the original shape (or other characteristic) of a signal. In communications and electronics it means the alteration of the waveform of an information-bearing signal, such as an audio signa ...

and

astigmatism Astigmatism is a type of refractive error due to rotational asymmetry in the eye's refractive power. This results in distorted or blurred vision at any distance. Other symptoms can include eyestrain, headaches, and trouble driving at n ...

. The high–

refractive index In optics, the refractive index (or refraction index) of an optical medium is a dimensionless number that gives the indication of the light bending ability of that medium. The refractive index determines how much the path of light is bent, or ...

, low-

dispersion Dispersion may refer to: Economics and finance * Dispersion (finance), a measure for the statistical distribution of portfolio returns * Price dispersion, a variation in prices across sellers of the same item *Wage dispersion, the amount of variat ...

glass additionally helps reduce

chromatic aberration In optics, chromatic aberration (CA), also called chromatic distortion and spherochromatism, is a failure of a lens to focus all colors to the same point. It is caused by dispersion: the refractive index of the lens elements varies with the w ...

s. A

neutral density filter In photography and optics, a neutral-density filter, or ND filter, is a filter that reduces or modifies the intensity of all wavelengths, or colors, of light equally, giving no changes in hue of color rendition. It can be a colorless (clear) ...

with approximately ND8 (3 f-stops) is employed for shooting in high light levels where normally a smaller aperture would be set. Although the lens is named a

, it has almost nothing in common with the 4 element in 3 group, non-aspherical original Tessar. Due to the comparatively large 1/1.2 in sensor and the comparatively fast lens with f/2.4 aperture, the camera has a quite shallow depth of field, equivalent to approximately f/7.8 at 26 mm on 35 mm full-frame.

Shutter

The 808 has a mechanical shutter with short shutter lag and ND8 (3 f-stops)

Audio

The 808 PureView employs Dolby Headphone software to transform stereo content to surround via a 3.5 mm A/V jack. It also includes Dolby Digital Plus software to provide 5.1 surround sound via HDMI or DLNA. The dual software elements from Dolby are embedded into the Nokia Belle feature pack 1 OS. The 808 PureView is the first device to include the Nokia Rich Recording technology and has a frequency range between 25 Hz to around 19 kHz. The 808 PureView can capture sounds at the loudness level of up to 145 decibels without distortion. The two microphones, located at the top and the bottom enable ambient stereo recording. The audio encoding is done in AAC high profile, 256 kbit/s, 48000 Hz.

References

External links

Nokia: PureView imaging technology - WhitepaperNokia: Nokia 808 PureView Device Details
{{Nokia 3-digit series Mobile phones introduced in 2012

808 808 may refer to: Music * Roland-808, Roland TR-808, a drum machine * 808 (film), ''808'' (film), a documentary about the Roland TR-808 * 808 State, British electronic group * ''808s & Heartbreak'', the fourth studio album by American Hip hop artis ...

Smartphones Symbian devices PureView Mobile phones with user-replaceable battery