PDF《PureView imaging technology》

4 PureView imaging technology. For example, with the default setting of 5Mpix (3072 x 1728), once the area of the sensor reaches

3072 x 1728, you'

ve hit the zoom limit. This means the zoom is always true to the image you want. New depth, new detail The way Nokia PureView Pro zoom works gives you many benefits. But the main one is undoubtedly '

pixel oversampling'

. 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. The level of pixel oversampling is highest when you'

re not using the zoom. It gradually decreases until you hit maximum zoom, where there is no oversampling. At this stage, Nokia PureView Pro optics and pixels start behaving in a more conventional way. But because only the centre of the optics are used where there is less diffraction, you get better optical performance ― including low distortion, no vignetting, and high levels of resolved detail. And because all of this is taken care of for you, you don'

t need to think about it, the system gives you the best balance between zoom and oversampling based on how you frame and compose the scene or subject. There are plenty more advantages… Figure 2. Oversampling vs. Zoom in the case of 4:3 aspect ratio ?2012 Nokia

5 PureView imaging technology. Purity of detail. Even digital SLR images have a certain softness. With oversampling, however, images can be noise free, yet incredibly detailed and defined. Zoom into the 5Mpix images at 100% magnification on your PC screen, and you'

ll see. There'

s something beautifully pure about the detail ― not enhanced in anyway. Look closely at some grass… it'

s amazing. Faster shutter speeds. 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. e.g. If a conventional digital camera set to ISO

100 uses a shutter speed of 1/30th second, the Nokia

808 PureView uses 1/180th second in the same lighting conditions. Or, looking at it another way, if a digital camera uses ISO

600 for a shutter speed of 1/30th, the Nokia

808 PureView could maintain the same shutter speed with ISO

100 ― significantly reducing the visual noise you'

d see in the resulting image. This also means that the Nokia

808 PureView'

s effective flash range is virtually maintained at all zoom levels, rather than being significantly reduced as the zoom increases. Goodbye to distortion. Distortion on all images is negligible. Whereas with optical zoom, images tend to get more distorted towards the edge of the frame (with bent vertical and horizontal lines) at the top of the zoom range. Silent zoom. The zoom function is completely silent ― which is really important when shooting video. Less is more. The simple structure of Nokia PureView Pro beats more complicated designs hands down. Image definition is pin sharp, way superior to conventional zoom designs. Conventional designs need many more lens elements to provide the zoom capability and correct aberrations, but these interfere with definition and/or light transmission. ........