Smartphone camera resolution has been increasing at a steady rate, with OEMs fueling a megapixel arms race. Because of physical size constraints for the sensor package, however, increasing the number of pixels generally means making them smaller. But smaller pixels capture less light, reducing dynamic range and low-light performance. Some OEMs, such as HTC and Apple, have favored using fewer, larger pixels to improve low-light capability at the expense of image detail.
With camera performance a high priority, Samsung is opting out of the megapixel race, choosing a completely new lower-resolution sensor with larger pixels for the Galaxy S7 and S7 edge. The 12 MP rear camera, the same resolution as the iPhone 6s, has 1.4μm pixels. There's also a new lens array with a larger f/1.7 aperture that lets in 25% more light than the f/1.9 aperture lens in the Galaxy S6. Combining the sensor’s larger pixels with the lens’ lower f-stop allows the new camera to capture 95% more light than the previous generation, according to Samsung. It will be interesting to see if this new camera can actually outperform the Galaxy S6, which currently has the best smartphone camera we’ve tested, at least when using the 16 MP Sony IMX240 Exmor RS sensor (some Galaxy S6 phones use a Samsung S5K2P2 ISOCELL sensor that does not perform as well).
The demonstration shown in the video above—conducted by Samsung—shows a tantalizing hint of the new camera’s performance by pitting the Galaxy S7 against the iPhone 6s Plus. When the light inside the box is dimmed, the Galaxy S7 certainly appears to capture more light.
This video also shows off the Galaxy S7’s autofocus capability. The Galaxy S7, like the S6 and most other premium phones, uses phase detect autofocus (PDAF), which provides superior performance to the contrast detection method. However, the S7’s new camera sensor uses far more pixels for phase detection: Where the Galaxy S6’s sensor only uses 0.78% of its total pixels as phase pixels, the S7’s new sensor uses 100% of its pixels. Samsung says that each pixel in its Dual Pixel sensor is split into two photodiodes. We're still not sure exactly how this works, but it seems to perform well based on Samsung's limited demo.
The other thing we're not sure about is if customers will still need to play the camera lottery with the S7. Samsung won't say, but based on the novelty of this sensor it seems likely that it's made by a single manufacturer.