The Nokia Lumia 1020’s astonishing camera is winning over everyone from technology critics to award-winning photographers from the National Geographic.
It’s no idle boast to say that it’s the best smartphone camera ever made.
In his review of the Lumia 1020 for The Verge, David Pierce wrote:
I don’t know how Nokia does it, or how no one else has figured out what Nokia is doing, but clearly there’s some kind of magic happening in Finland.
One of the people responsible for making the magic happen is Eero Salmelin, Nokia’s Head of Imaging.
“It’s easy to make a device that is big and bulky with good imaging, and it’s easy to make a thin phone but the image quality would suffer,” says Eero.
“Finding the best balance between the imaging performance and the beautiful industrial design is critical.”
Here, Eero goes into more detail about each of the crucial hardware components inside the Lumia 1020’s awesome camera.
First we have the optics system with its six element lens, which Eero says is the highest performing optics ever been put into a Nokia device.
The optics captures all the light from the scene and focuses it on top of the image sensor, thus forming the image. A wide angle lens is also used for a wide field of view – everyone can fit in the picture.
There are many different parameters that affect the optics and the sharpness of the images that they can produce. The imaging team were determined to improve upon the optics that they had created for the Nokia 808 PureView. So the F-number was improved from the 808 PureView’s f 2.4 to f 2.2 in the Lumia 1020 – this allows even more light through and improves the performance in low light conditions.
“Together with ZEISS, we went through many, many optics designs and technologies in order to come up with optics that were slim enough to fit inside the Lumia 1020,” reveals Eero.
The auto-focus enables the camera to focus at different distances. This means that the lenses need to move up and down, to vary the distance between the lens and the image sensor.
“This is done in the Lumia 1020 by very small but yet very strong voice coil motor. Together with auto-focus algorithms it decides where the lens needs to move and then the motor is physically moving the lens to the right position. This enables sharp pictures.”
Optical Image Stabilisation (OIS)
Shaky hands are a common problem when people are taking pictures. In Nokia’s OIS solution the whole lens system is resting on ball bearings.
“The special gyro components are very accurate and fast in detecting how the phone is moving and the lens is moved by the motors in the opposite direction very quickly to compensate for the handshake.”
The headline-grabbing 41-megapixel sensor is the component that collects the light and which eventually forms your beautiful pictures.
“We are using a Back Side Illuminated (BSI) image sensor, which is a technology where the metal wires in traditional sensors are now moved to the other side, so there is no metal wiring trapping the light from the image sensor. This makes the sensor more sensitive to light,” says Eero.
The sensor doesn’t work alone – there’s also some clever image processing involved. We’ll hear more about this later.
As Stephen Elop demonstrated at the Lumia 1020’s launch, it also has a great Xenon flash.
“It offers a really nice light spectrum and the colour is very close to sunlight so it means you can have really accurate colour reproduction. Another benefit of Xenon is that the light comes as a very short pulse so it helps to stop the movement in the picture. It’s also great in typical use case when light is behind the target providing a nice fill in flash”
The Xenon flash can make all the difference when you’re taking photos in low light, or in the dark. Eero reveals that the Lumia 1020 has the most powerful Xenon flash that Nokia has ever used. Embedded within the flash is also the video light and autofocus assist light which helps attaining focus in the dark.
The camera module is the casing that packages everything together so that it slots neatly inside the Lumia 1020. It measures 25mm by 17mm and contains well over 130 individual components.
“Every single camera component is tested, calibrated and the quality is verified. We make sure that each module performs extremely well,” says Eero.
“The overall module design was also key to making the Lumia 1020 a sleek package.”
The final component is not, strictly speaking, a component at all. Capturing the light through the optics and then focussing it on the image sensor is just the beginning.
Nokia’s image oversampling algorithms take millions and millions of samples every time you take a picture. The raw data is put through a huge number of different algorithms in order to produce the final image with great colour reproduction and sharpness.
For Lumia 1020 we have improved many of the critical image processing algorithms like white balance, autofocus and many more.
Eero says: “Image processing is a critical piece of the magic in Lumia 1020.”