Early Thoughts on the Nokia 808 Pure View

Posted on 02/28/2012

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I have spent the past 24 hours digesting the key elements of Nokia’s Mobile World Conference presentation yesterday, the new Symbian powered device, the Nokia 808 PureView. What started as shock, turned initially into horror, then bemusement and finally into awe. Lets take a step back. If you have ever read this blog you will know that I’m a very happy Nokia N8 user, even after dipping my toes into Android at the end of last year, with the best of the lot the Samsung Galaxy S2. Say what you will about the merits or lack thereof of owning and using a Symbian device in 2012, but for my use, the Nokia N8 was and remains the one. I explained this in a post I wrote last year, summarised simply as: “it’s all about the hardware”.

The Nokia N8 running Belle, with a stable if somewhat static ecosystem, is more than good enough such that the hardware more than makes up for it’s shortcomings. At the heart of this incredible gadget was a camera that has remained unsurpassed, at  least for stills since it’s launch over 18 months. The headline specification at launch was 12 million, the number of pixels contained in the sensor. Focussing on that specification alone does not do justice to what Nokia achieved with the N8 in 2010. The numbers that I prefer to focus on are rather, 1/1.83″, 37 mm2 , 320 000 and 1.75 microns, the image sensor size in optical format, the image sensor surface area, the number of pixels per mm2 and the size of each individual pixel. These are not as sexy as the raw resolution but give more insight into why the N8 possessed such a beast of a camera, and why I have never felt the need to invest in a point and shoot camera since I got mine at the beginning of last year.

The N8 sensor was huge by cellphone standards and compettive with dedicated point and shoot cameras. Something that sales people neglect to tell shoppers is that the raw resolution is hopeless if the sensor is small and not sensitive, and if the optics are poor. Light is the tonic that makes cameras tick and a large sensor means that the light gathering capability of a camera is greatly enhanced. This means that more information is available to process the image. Also important is the density of the pixels on the surface of the sensor. Something never spoken about as megapixels are headlined is that there are only so many pixels you can cram onto a sensor before the quality of the image is actually adversely affected.  As pixels get closer and closer to each other, you will end up with excessive pixel crosstalk, and confusion in image processing. Lastly the bigger the pixel the better it is at capturing light but conversely if pixel count goes up and sensor size remains constant, then at some point once saturation is reached, the only way to accommodate the extra pixels is to decrease  the size of the pixel. This in turn reduces the light gathering ability of the sensor.

By all accounts the N8 scored good marks with all these parameters, which were in line with the dedicated camera industry explaining why it took such fabulous pictures, and remains at the forefront of the mobile industry. There was a tradeoff with the N8, something affecting all camera phones, the lack of true optical zoom. Unfortunately until we accept fatter devices, even fatter than the already hefty N8, optical zoom remains a pipe dream.

Well not anymore.

Yesterday, Nokia dropped a ludicrously crazy bombshell on the mobile industry. It is easy to get carried away when describing the Nokia 808 Pure View but no doubt the headline specification doing the rounds will be its astonishing 41 megapixel sensor and also being the first Nokia device to record video in full HD resolution, 1080p. As the presentation yesterday took place, much of what I heard before and after Pure View tended to be a blur as I digested what I had heard. My initial thoughts were that it was not possible as there were very few technical details available. Physics just dictates that 41 MP is just an impossible amount of pixels to cram onto a sensor in a phone. And who needs that many pixels anyway? Throughout the day, details began to surface and it became apparent what Nokia is trying to achieving with the 808 Pure View, that unfortunately will get lost beneath the murky waters of the megapixel race.

Let’s repeat the same exercise I did with the N8. Forget the raw resolution and look at the 808 camera differently. The numbers to focus on now are 1/1.2″, ~86 mm2, 480 000 and 1.4 microns.  The first thing we notice, as expected is that the 808 Pure View has a HUGE sensor, with nearly 2.5 times the surface area of the N8. What is interesting though is that even with this gain in surface area, there has been a compromise on the last two measures, with pixel density 50% higher than the N8 and pixels that are 20% smaller than the N8. Those numbers are actually not that bad but that’s is only if we become fixated on the raw resolution of the 808 Pure View, which with a sensor that supports multiple aspect ratios, ends up with images that are 38 MP in 4:3 and 34 MP in 16:9. Still pretty hefty. You see what has become apparent is that the 808 Pure View is not designed as a 38 MP shooter. Other than the ridiculousness of sending out such high resolution photos, there is the impracticality of the fact full size images captured are approximately 10 MB in size.

The first clue to the use case of Pure View was that the first screen shots showing the camera interface had the resolution set to 5 MP, which it turns out is the default setting. While there is a ‘creative setting’, ie maximum resolution, the 808 Pure View also has settings for 3 MP and 8 MP. This is where it gets clever. Really clever. When shooting video, the N8 (and the N86 before it) utilizes the full 12 MP sensor, then essentially takes the best parts to produce the 1280×720 video or roughly 960 000 pixels, binning roughly 90% of the information. Moreover when you zoom into video, it is essentially lossless. The Pure View is this same concept on a serious dose of steroids.

By discouraging the use of ‘creative mode’, users will reap maximum reward from the pixel oversampling system of the 808 Pure View. For example when shooting in 8 MP you are looking at information recorded on 5 pixels being condensed into a single super pixel that removes the worst parts and keeps the best information, the perfect pixel. Even better is that you now for the first time have lossless zoom like on video on a phone without the added bulk of an optical zoom system. This essentially means that at the standard viewing angle, 26-28 mm you should be getting significantly better images at the reduced resolutions of 3 MP, 5 MP or 8 MP than if you used a camera phone of similar resolution without the Pure View system. You have the benefit of  shooting  standard resolution images on a ridiculously large sensor with all the added benefits like low noise, improved low light performance and increased dynamic range, enhanced by the oversampling of pixel data. And even once you’ve reached the zoom limit, which say at 5 MP will be a true 5 MP image,  of 2592×1944 (at 4:3), then you have an image shot with a pixel density and pixel size that is comparable to competing devices, but with the benefit of the technology and the optics in the 808 Pure VIew.

Just think about that for a second. Even at the zoom limit of the 808 Pure View you should in theory get an image that is still the same quality as competing devices.

The proof will be in the pudding of course and we need to see exhaustive images to see if Nokia have pulled this off. Samples images are trickling through already and by all accounts, the Pure View has shifted the goal posts even further. I was surprised by the maximum resolution images, which have an astonishing amount of detail but there are signs of more aggressive image processing than has been norm with something like the N8. Where the Pure View shines however is in the oversampled images. We are seeing the future of mobile photography now, and is it surprising that it is Nokia pushing the envelope.

The 808 Pure View is an enhanced Nokia Belle device, which has upset a few people, but as I said, for me personally Belle gets the job more than done. As far as Symbian devices go, the 808 Pure View is the best stocked to date, with a 1.3 GHz SoC and 512 MB RAM. It has all the goodies we have come to expect from Symbian devices, FM transmitter, HDMI, NFC and a whole host of other hardware pleasure. In case you were wondering how this devices handles the monster images, there is special companion processor that aids the image processor with pixel scaling. It also introduces other enhancements like Nokia Rich Recording that improves improves the already stellar audio recording on the N8. Non Symbian aficionados will be happy to know then that the 808 Pure View is not a once off and this technology looks like it is here to stay and will be found in other Nokia Pure View devices in the near future.

The Pure View was five years in the making and it shows. As a proof of concept it is simply mind blowing and even better is its immediate application and usability. It’s not about the crazy numbers on show but rather about about genuinely allowing mobile phone users to take better photos within the physical limitations imposed by the nature of the mobile phone.

Good job Nokia. Good job.

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