Nokia 808 PureView: How It Works, 41mp Smartphone Cam Deep Dive

aNewDomain.net — UPDATE June 8, 2013: Everyone is asking about the 41mp smartphone camera tech from Nokia that’s now available widely on the Nokia PureView 808. How does it work? That’s a mighty big spec. Our Julie Blaustein did a deep dive. Nokia announced the 41mp pixel-binning cam last year in Barcelona at Mobile World Congress and no one could believe it then, either — so she took a closer look. Deep tech explainer below.

The Nokia 808 PureView commercial, above, was shot with a PureView smartphone, reps at Finland-based Nokia say.

If you’re into cameras, you couldn’t miss the excitement surrounding Nokia’s announcement of its 41mp Symbian-based Nokia 808 Pureview early this year.

Nokia announced this 41mp camera equipped Symbian smartphone at MWC 2012 in Barcelona — with a splash — in February. Reactions varied from wonder to disbelief. They still do. After all, 8mp is typically the best spec you’ll see on the latest smartphone cams, excepting Nokia’s own Nokia N8 Symbian model.

Available for pre-order in several European outlets now and scheduled to ship in May — pricing is 600 Euros and up — specs include:  a single-core 1.3Ghz processor, 512MB of RAM, 4-inch AMOLED screen, 16GB internal storage and the capability to shoot 1080p video.

But it’s that giant 41mp res camera — running, as it is, on Nokia’s Symbian Belle OS — that is turning heads. Nokia reps confirm the 41mp technology will be running on Microsoft Windows Phone 7.5 and 8 by the end of the year. Pics of it running on a dual-core Windows Phone based Nokia 808 PureView are flooding the web. So why the hubbub? Who needs a smartphone with 41mp resolution and how does this giant res camera work?

According to Nokia, enhanced zoom and the capability to enlarge images through its zoom are the 808 PureView’s main benefits. But there’s more to the story. Here’s a deep look at what’s behind this technology. Let’s start with the lens.

Zeiss Lens Tech

Before we get into the resolution, consider the lens in this camera — the 808 PureView employs a Zeiss lens. That’s key. A camera is only as good as its lens, after all, and a Carl Zeiss Optics lens is top drawer.  It’s great in low light and other difficult lighting situations. Interestingly, the partnership between Nokia and Zeiss came about in 2004, back when the two firms were collaborating on the Nokia N90. Zeiss has been on the cutting edge of optics since its founding in 1846, back when its founder built his first microscopes.

Enormous, Ultra High-Res Sensor

A great lens doesn’t mean much without a standout sensor and, according to its specs, this is where the 808 PureView really shines. It employs an enormous, high res sensor. The bigger, the better. Nokia says the sensor on this smartphone camera is able to capture 7728 x 5368 pixels – that is a total of 41mp.

That sensor resolves at about five times the size of what the average smartphone employs — 8mp is the standard on high-end smartphones these days, and the largest one shipping is 12mp. This 41mp sensor is about three times larger than the sensor on most pro-level compact cams. All those pixels translate into ultra-sharp images and the capability to zoom in — with total clarity and no noticeable visual noise.

This chart, included in a piece at dpreview.com, is a great demonstration of what I’m talking about.

Credit: DP Review

Pixel Binning Technology

Is pixel binning technology the secret sauce of the Nokia PureView 808? Its not just the pixel binning. That much is clear.

Pixel binning, also known as over-sampling, is the technical term for taking several pixels and combining them into one pixel. Pixel binning has traditionally been used in low light photography, especially in astronomy. The primary benefit of pixel binning is it improves the signal-to-noise ratio (SNR) in low light conditions, which ultimately determines the performance of a camera. In the case of the 808 PureView, its pixel binning takes seven pixels of information and condenses those into one single pixel, which in turn provides a sharp 5mp image. Nokia claims its use of proprietary algorithms for optimizing detail retention, combined with pixel binning, is what makes this super camera tech possible.

As a result — and this is truly the standout capability here and the benefit of having such a high-res camera — you get serious zooming.Nokia claims the 808 PureView users will be able to zoom into any portion of a pic — at up to 3x — without losing any of the details in your shot. And on top of that, you lose most of the noise.

Nokia certainly isn’t the first to do pixel binning, nor does Nokia have a patent for it. I did a search via Google Patents and found a list of patents and applications associated with pixel binning. Most noteworthy is US Patent 7,233,354, filed by Hewlett-Packard Development Company, L.P. on October 11, 2002 and issued on June 19, 2007. Its description is for a “digital camera that adjusts resolution for low light conditions.”

 

Credit: Camera System Design 

 

In this video, Nokia illustrates the benefits of this enhanced zooming. 

 

Creative Shooting Mode

By default, The 808 PureView provides a 5mp image, which allows for 7152 x 5368 pixels. It also, Nokia says, features a special so-called creative shooting mode if you want the full resolution.

At most, the camera offers a 38mp at 4:3 aspect ratio. The aspect ratio describes the proportional relationship between an image’s width and its height. And at a 16:9 aspect ratio, your images are at 36mp.

Why not 41mp as advertised?

It’s not false advertising — the sensor, as outlined in the specs, does have the capability of 41mp, a total of 7728 x 5368 pixels. But as the optical format area in a camera is a circle, not a square, a few pixels are left out in the final image.

As you see in the illustration provided by Nokia below, the 38mp at a 4:3 aspect ratio makes full use of the height of the image sensor and at most is 7152 x 5368 pixels. At 34mp and a 16:19 aspect ratio it makes full use of the Height of the image sensor and at most 7728 x 4354 pixels.

Credit: Nokia PureView White Paper

Not only does this camera provide great resolution due to its Carl Zeiss optics and sensor, it provides full zoom, captures over 5x more light and, thus, faster shutter speeds. It also reduces the ill effects of camera shake, Nokia claims, but the proof for that will be in the review.

Video

In addition to all that is available as a camera for the PureView,  Nokia claims the cam on its phone shoots 1080p video. It features what Nokia calls ultra high quality stereo audio recording due to its partnership with Dolby. While most high end smartphones can only record without distortion to around 110db, the 808 Nokia is able to reach up to 140-145 db, at least according to Nokia’s white paper.

That’s about four times louder than conventional mics can record. It also, Nokia claims, is capable of recording low frequencies also without any distortion. The combination of all of these elements means the 808 Nokia records audio with almost CD like quality, say Nokia reps.

The Waiting Game …

Nokia spent 5 years in development for the 808 PureView. In that time Nokia phased out of the Symbian OS in favor of the Windows Phone. But this tech is debuting on Symbian Belle, and is headed for Windows Phone 8, sources close to the company say. Similar tech with pixel binning plus image optimization is expected from Samsung and Apple later this year … Nokia, Apple, Samsung, Microsoft and other tech companies reportedly have access to one another’s patents via their partnership with mass patent aggregator Intellectual Ventures …

Images: Nokia