Nokia 808 Phone Features 41MP (!) Sensor

Nokia announces 808 PureView smartphone featuring its PureView imaging technologies - a combination of high resolution sensor, Carl Zeiss optics and Nokia developed algorithms.

The Nokia 808 PureView features a large, high-resolution 41MP sensor with new pixel oversampling technology. At standard resolutions (2, 3, 5 and 8 megapixels) this means the ability to zoom without loss of clarity and capture seven pixels of information, condensing into one pixel for the sharpest images imaginable. At high-resolution (38MP maximum) it means the ability to capture an image, then zoom, reframe, crop and resize afterwards. The new camera phone is said to have a superior low-light performance.

The Nokia 808 PureView is also capable of full HD 1080p/30fps video recording and playback with 4X lossless zoom.

The sensor size is huge 1/1.2-inch, approximately 2.5 larger than the sensor used
in its predecessor, the 12MP Nokia N8. The pixel size is 1.4um.

The dedicated PureView page shows the phone with 41MP label on the camera and Youtube videos (Video 1, Video 2):

Nokia whitepaper reveals few more bits of information about the new sensor:

"So how is this possible?

The starting point is a super-high-resolution sensor. This has an active area of 7728 x 5368 pixels, totalling over 41Mpix. Depending on the aspect ratio you choose, it will use 7728 x 4354 pixels for 16:9 images/videos, or 7152 x 5368 pixels for 4:3 images/videos as is shown in Figure 1:"

"Pixel oversampling combines many pixels to create a single (super) pixel. When this happens, you keep virtually all the detail, but filter away visual noise from the image. The speckled, grainy look you tend to get in low-lighting conditions is greatly reduced. And in good light, visual noise is virtually non-existent. Which means the images you can take are more natural and beautiful than ever. They are purer, perhaps a more accurate representation of the original subject than has ever been achieved before."

"With the Nokia 808 PureView, you get effective maximum aperture throughout the zoom range. Whereas with optical zoom, less light tends to reach the sensor as the zoom increases. At maximum zoom, 5.4x more light reaches the Nokia PureView Pro sensor than a broadly equivalent optical-zoom digital camera (f/5.6 as opposed to f/2.4). And this means you get the benefit of faster shutter speeds."

The formal camera specs are:

The technology:
PureView Pro imaging specifications

• 41MP sensor with pixel oversampling
• Lossless zoom: 3x for stills, 4x for full HD 1080p video
• Carl Zeiss optics

The product:
Nokia 808 PureView lens and sensor specifications

• Carl Zeiss Optics
• Focal length: 8.02mm
• 35mm equivalent focal length: 26mm, 16:9 | 28mm, 4:3
• F-number: f/2.4
• Focus range: 15cm – Infinity (throughout the zoom range)
• Construction:
  · 5 elements, 1 group.All lens surfaces are aspherical
  · One high-index, low-dispersion glass mould lens
  · Mechanical shutter with neutral density filter
• Optical format: 1/1.2”
• Total number of pixels: 7728 x 5368
• Pixel Size: 1.4um

Regarding the pixel size Nokia writes:

"People will inevitably home in on the number of pixels the Nokia 808 PureView packs, but they’re missing the point. The ‘big deal’ is how they’re used. At Nokia, our focus has always been capability and performance.

The main way to build smaller cameras over the years has been to reduce the pixel size. These have shrunk just over the past 6 years from 2.2 microns, to 1.75 microns, to 1.4 microns (which is where most compact digital cameras and smartphones are today). Some new products are on the way with 1.1 micron pixels. But here’s the problem. The smaller the pixel, the less photons each pixel is able to collect. Less photons, less image quality. There’s also more visual noise in images/videos, and various other knock on effects. In our experience, when new, smaller pixel size sensors are first released, they tend to be worse than the previous generation. While others jump in, banking on pixel numbers instead of performance, we prefer to skip early iterations."

Update: Nokia Conversations, the official Nokia blog shows Youtube video of Juha Alakarhu, the head of imaging technology group:



Nokia also offers sample unretouched pictures from the camera here.

AllThingsD shows internals of the new Nokia camera and talks about the camera development process which took 5 years.

Update #2: As written in comments, The Handheld Blog published a video interview with Damian Dinning, the member of Nokia camera team, where he says few words about the sensor:



Update #3: Venture Beat published another video interview with an engineer from Nokia camera team showing sample pictures and explaining 808 camera decisions:



Nokia Conversations compiled a page of 808 camera reactions from the internet media.

Eero Salmelin, Head of Imaging at Nokia, features at I3A site (just a coincidence?). Just two months ago Eero won I3A annual Leadership Award.