Nokia Pureview 808 made quite the stir on the market earlier this year. The main reason – highest resolution sensor; not only amongst mobile phones, but even higher than all other digital camera except medium format beasts like Hasselblad, Phase One or Pentax 645. Is it just a marketing stunt or are the 41 megapixels actually usable in real life – that’s what I was eager to find out.
In this review, I will evaluate only digital camera capability of this smartphone; for everything else you might want to find a review written by a mobile phone oriented web site.
CONSTRUCTION AND HANDLING
Using this smartphone as a digital camera proved to be somewhat difficult. It’s a big flat but very thin device which is a joy to use as a smartphone. It rests in my palm perfectly while tapping functions with my thumb. But using it as a camera is another story. As I said, it’s very thin, at least compared to real digital cameras, so holding it with one hand and taking pictures is almost impossible. I couldn’t put my thumb on LCD (touching it would change some setting) and shutter button is on the far right, so my index finger had to be in a very unpleasant position, as can be seen on the picture left. I managed to drop the phone a few times, and if it wasn’t attached to my hand with hand strap, it would surely hit the floor and broke. But the same problem is valid almost for all smartphones, so if you’re used to it, this Nokia won’t feel any different in use.
SENSOR AND PROCESSOR
The main reason this smartphone attracted so much attention is the sensor used in it. With a size of 1/1.2″ it is bigger than those found in compact cameras and almost as big as the ones used in Nikon 1 series and Sony RX100. Resolution figure is hard to believe – it has 41 megapixels! Actually, it gives 38MP in 4:3 ratio and 36MP in 16:9 ratio effectively, but getting a picture with dimensions of 7152 x 5368 pixels from a smartphone is unheard of. Bumping pixel count is a practice all manufacturers use to gain new customers; it’s easy to attract buyers with vast megapixel numbers most of them don’t know what to do with. In most cases, especially with compact cameras and mobile phone cameras higher megapixel count meant more noise, weaker color reproduction and generally lower image quality. So I couldn’t wait to try Nokia Pureview if it is any good.
But the story isn’t that simple. Nokia didn’t just bump megapixel count because they could (well, partly they did), but used them in two special ways. Nokia 808 has a fixed lens; optical zoom assembly would still be too big for a smartphone. Instead, there is digital zoom, but one that really works without any degradation of image quality. Cleverly, Nokia uses its vast resolution for zooming – it simply crops center portion of huge 38 MP files. If set to lowest resolution of 3MP, you effectively get 3.6x zoom option. You might as well always shoot at highest resolution and crop afterwards (that’s what I did) but in reality, most customers are either too lazy or simply aren’t used to compose shots with prime lens, so it might be more logical for them to use lower resolution combined with zoom option.
The second advantage of humongous resolution is “Pureview” technology. It is actually quite simple; camera uses pixel oversampling – combining data from several adjacent pixel to create one new pixel with higher image quality. There are three smaller resolutions – 8MP, 5MP and 3MP. In theory, the lower resolution you pick, oversampling would produce higher image quality because more and more pixel would be combined. And of course, oversampling is not available when zoomed in; as I explained earlier, zoom actually means “crop” on this camera. When such case, there are no pixels left to be combined to “super” pixel.
Lens bears a “Carl Zeiss” name which should indicate its high quality. It has a constant aperture of F/2.4 and focal length of 8mm. In 35mm equivalent, this would give viewing angle of 28mm when used in 4:3 ratio or 26mm in 16:9 image ratio. Because of constant aperture and lack of optical zoom, DOF always remains the same.
The lens has a built-in ND filter, used in bright light conditions. Very nice detail, but there’s a catch with it. Camera prefers to use ND filter over raising shutter speed in almost any case. That’s why I ended up with some blurry photos in the middle of the day during Augusts bright sunlight. ND filter darkens the view too much so the camera chooses shutter speeds of around 1/100 in bright sunlight when it could go much higher. 1/100 is sometimes not enough to freeze even people walking on the street. ND filter can be turned off manually, but I wonder how many buyers will be able to understand they need to do it when shooting moving objects.
Generally the lens is really good, very sharp and capable of delivering details to high resolution sensor and with no light falloff in corners. It does produce a small amount of chromatic aberrations though (easily removed on PC), and has a rather pronounced flare when strong light source like Sun are in the frame (examples below).