Nokia Lumia 1020 review
Windows Phone 8, 4.5in 1,280x720 display
The Lumia 1020 is Nokia's attempt to build the ultimate cameraphone. It's a Windows Phone 8 handset with an enormous 41-megapixel camera sensor, and it uses some seriously clever tricks to produce the best phone images we have ever seen.
We saw the first version of Nokia's large sensor on the PureView 808, but our enthusiasm was tempered by the handset's soon-to-be-defunct Symbian operating system. The Lumia 1020 has no such problems, as it runs Microsoft's increasingly-popular Windows Phone 8.
The PureView camera sensor is more than just a huge collection of pixels. It's physically larger than the sensors in most smartphones and even some compact cameras. At 1/1.5in, it's twice the size as the sensors in phones such as the HTC One, Apple iPhone 5S and Nokia Lumia 925, and 1.5 times larger than the sensor in our Best Buy-winning Canon Ixus 255 HS compact camera.
Generally, the bigger the sensor, the more area there is to capture light and so the less image noise and better low-light performance. The Lumia 1020's sensor is also a backside-illuminated (BSI) model, where light strikes the sensor from the rear, avoiding any circuitry getting between the light and the sensor's photoreceptors.
This isn’t the only trick up the 1020's sleeve, though; Nokia has also decided to use the sensor's huge number of pixels to help improve image quality further. When you take a picture with the Nokia Pro Cam app, the phone saves two versions; the full 7,712x4,352 pixel image and a smaller 3,072x1,728 (5-megapixel) snap.
There are two reasons to have the smaller image. The first is that it's small; around 1.6MB compared to the 9MB or so for the full-fat version, making it much easier to upload straight to a social network. The second is down to something Nokia calls oversampling. This examines each pixel in the larger image, then works out which it should keep and which should be discarded to make the smaller image the best possible quality.
The big camera assembly adds a bulge to the back of the phone