Dual-pixel technology explained

May 04, 2016

HTC created ultra-pixel technology for their 2013 flagship the HTC One; they believed a 4MP camera with such tech could outdo the 16MP camera of the Galaxy S4 which was the rival at that time. As we all know, that didn’t work out too well; most people didn’t appreciate the picture quality.

Samsung have done a similar thing this year with the release of the Galaxy S7, by reducing the pixel count, down to 12MP and backing it up with dual-pixel technology. So just what is this new tech, and is it bound to fail like the HTC’s venture?

What is dual-pixel

In essence, dual-pixel technology is an imitation of Phase Detect technology found in DSLR cameras. Phase detect is done by individual photodiodes in a camera’s sensor that detect light from an object; these photodiodes detect minor variations in colour and create contrast. Usually, a smartphone camera relies on its pixels to receive light from the source and then the camera software tends to sharpen the image by determining contrast levels. This is the reason for most of the ‘noise’ you find in an image when it’s zoomed in.

DSLRs have a much larger sensor and can therefore fit these phase detect diodes to improve on contrast and sharpen images which is why the pictures are so crisp. Apple tried to integrate phase detect into their iPhone 6, too, but the photodiodes dedicated to phase detection were scattered around and consisted about 5 – 10% of the total sensor’s surface area. They couldn’t add so many of them because their camera was only 8MP at the time.

To combat this problem, Samsung have chosen to pair each pixel with a phase detection diode, radically raising the number of photodiodes dedicated to phase detection. To prevent cross-talk between the pixel and phase detect diodes, they had to come up with ISOCELL technology as well, which is essentially a wall between these two components.

Because now the sensor had to cater to both the pixels and phase detection diodes, the individual pixel areas had to be larger, 1.44 microns, and only a maximum of 12MP was possible. Nevertheless, the combination of the two systems has radically changed smartphone camera technology and you can expect to see more of this in future.

How successful is it?

Now that you know how the technology works, I’m sure you would like to know how it performs in practice. The answer is, superb, and in a lot of ways:

  • Speed: picture taking would take a few milliseconds because software had to analyse and sharpen the image. Dual-pixel technology requires less post-processing and pictures are instantaneous
  • Clarity: every picture taken is sharp as it can be. Zooming into pictures taken in good lighting will amaze you because even when zoomed in the quality is still excellent. Sometimes you might get a bit noisy images in the dark when you zoom in, but that’s only because little light reaches the pixels.

This technology will definitely not fail, if anything, it will be improved in the future and maybe even copied by other manufacturers. Bottom line, the new Galaxy S7 camera will not disappoint at all but rather astonish you.


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