The Nokia N8 has been the best camera phone on the market for the past one year, even coming close to a DSLR in good light. The PureView 808 with its 41 Megapixel sensor promises to take that title away from its very able predecessor. The photo quality of the new smartphones that were announced recently were just amazing that they rival even the top point-and-shoot phones and even entry-level dSLRs.
Having done a bit of analysis of this picture, I’m pretty sure I can see near pixel level detail in those cables or at least 2px level detail. This is amazing for a lens never mind a sensor! The lens, out of interest, is supposedly built to a tolerance surpassing that of DSLR lenses, 10x so according to the PR surrounding this camera. I think this must be to do with the lens system, not the lens itself. I can imagine this to be true because just the construction of larger lenses – plastics involved, machining etc, may be a source of innaccuracies.
(Photo credit: Nokia Press)
Having done a bit of analysis of this picture, I’m pretty sure I can see near pixel level detail in those cables or at least 2px level detail. This is amazing for a lens never mind a sensor! The lens, out of interest, is supposedly built to a tolerance surpassing that of DSLR lenses, 10x so according to the PR surrounding this camera. I think this must be to do with the lens system, not the lens itself. I can imagine this to be true because just the construction of larger lenses – plastics involved, machining etc, may be a source of innaccuracies.
However they’ve managed this, it’s damned impressive. Let’s take a look at some of the specifications for the camera system.
- Xenon flash with operating range up to 3.5 m depending on conditions. Automatic fill-flash
- Focal length: 8.02 mm f/2.4 (35 mm equivalent focal length -26 mm, 16:9 / 28 mm, 4:3)
- Lens: 5 aspherical elements, 1 group.All lens surfaces are aspherical, one high-index, low-dispersion glass mould lens
- Shutter: Mechanical shutter with neutral density filter
- Focus: Hyperfocal, Macro, Infinity and Auto; range – 15 cm ~ infinity
- Aspect ratios and resolutions: True 16:9 (2 MP, 5 MP [Default], 8 MP, 41 MP) 4:3 (3 MP, 5 MP, 8 MP, 41 MP)
- Image size: 7728 x 5368
- Still images file format: JPEG/EXIF
- Pizel Size: 1.4um
- Automatic location tagging (Geotagging) of images and videos
- 16 GB internal user memory and support for up to 48 GB with an external microSD memory card
- Weight: 169g
The standout information here are the Carl Zeiss lens… five aspheric elements and one full glass mould coated element. That’s a pretty damned complicated lens! On top of this we have a 35mm equivalent focal length of around 28mm (3.5x crop factor) – nicely wide enough for landscape. The only sad news is no RAW but, hey, this is a phone camera!!
According to Nokia …
“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.”
So there seem to be quite a few benefits involved here. What does this say about camera sensors though? Well there are obviously quite a few compromises involved here but, looking at the pictures it certainly seems like Nokia have produced a sensor that could provide the basis for movement beyond the current sensor designs. This ‘oversampling’ allows different colour sensor distributions and also introduces the possibility of have more than three colours (a hexacolor sensor filter perhaps with a clear pixel – perhaps that’s why there are 7 sub-pixels?).
I expect this technology to make it’s way into compact cameras quite soon which will make some interesting possibilities. For a start, at this pixel density a micro four-thirds camera could have an image size of 12,500px by 9,300px for a sum total of 116 megapixels.
A lot of people may say “What about diffraction?” – well, at the f/2.4 aperture that the lens has, the diffraction ‘spot size’ is 3 microns – this just happens to be twice the size of the pixel sensor. Handily, this means that diffraction is acting as a built in anti-aliasing filter, averaging the light over the (probable) different coloured pixels in a sub-pixel set!
What I expect to see is a 40-60 megapixel micro four thirds (or similar size sensor) camera built on this technology using down sampling to produce critically sharp 10-15 megapixel images.
