Camera Performance and Quality
Inside the Galaxy S7 and S7 Edge we're getting all-new cameras. Gone is the old 16-megapixel sensor with 1.1 micron pixels, instead replaced with a 12-megapixel Samsung S5K2L1 (or Sony IMX260) 1/2.5" CMOS sensor with 1.4 μm pixels. This is a downgrade in camera resolution, but the increase from 1.12 to 1.4 microns equates to a 56% increase in light gathering ability.
The lens that accompanies this sensor is a 25mm-equivalent with an aperture of f/1.7, which again is an increase in light gathering ability of 25% over the f/1.9 lens on the Galaxy S6. Combined with the pixel size increase, around 95% more light is being captured by this camera system overall, which is a huge improvement over the last generation. Optical image stabilization is also included to complement the package.
On the front is a 5-megapixel Samsung S5K4E6 sensor, which appears to be the same 1/4.1" sensor with 1.34 μm pixels as the Galaxy S6, paired with an f/1.7 23mm-equivalent lens. Again, the increase in aperture from f/1.9 to f/1.7 provides a 25% increase in light capturing ability. Both the front and rear sensors are native 4:3 in aspect ratio, with the rear sensor ditching 16:9 in favor of the more common image format.
The rear camera is equipped with a single-LED flash, and it can record footage up to 4K in resolution at 30 FPS. It's also capable of 1080p60 recordings, as well as 720p slow motion footage at 240 fps. The front camera is locked to just 1080p30 recording due to its limited resolution and hardware.
The big innovation that Samsung has made in their rear camera with the Galaxy S7 is dual pixel technology. This refers to how every pixel in the sensor is split into two photodiodes, which allows phase detection autofocus to occur at every point on the image. For actually capturing images, the two photodiodes combine their information into one 1.4 μm pixel, delivering what should be very comparable low light performance to standard 1.4 μm sensors.
Dual pixel technology allows the Galaxy S7 and S7 Edge to have the fastest camera autofocus system I've ever seen on any camera. As the camera can gather focus information from every pixel, it always knows where the image is in focus, and it can make near-instantaneous measurements and adjustments to keep focus. If you bring an object into the camera's field of view or move the camera itself, the S7 will gain correct focus in mere miliseconds. Tap anywhere on the screen and you can expect similar results.
With such fast autofocus, you never have to wait for the Galaxy S7 to find the correct focus before taking an image. You simply point at an object and immediately press the shutter button, and you'll get a great image. It's particularly useful for moving objects; the S7 can very quickly adjust its focus as objects move around the field of view.
Image quality from the S7 Edge is excellent in a wide variety of situations. In strong lighting, great dynamic range and contrast combined with auto-HDR delivers rich, detailed and vibrant images that come close to replicating real-world scenes. Despite a downgrade in resolution, sharpness and clarity is still excellent from this camera's 12-megapixel stills, and zooming in reveals few artefacts in all but wide shots, indicating Samsung has toned down their noise reduction and sharpening filters present on the S6.
The f/1.7 lens delivers very respectable bokeh for a smartphone camera, which gives a pleasant background blur to macro photos and close to mid-range shots. Despite the wide aperture, the narrow depth of field was easy to manage in most situations, and it's only in the closest focal distances that it starts to make a difference to how much of an object is in focus. Even then, you can get some stunning macro shots out of this camera.
Great image quality continues when shooting indoors and in other less ideal conditions. The increased light gathering ability of this camera means that the S7 Edge can use shorter shutter speeds and lower ISOs when shooting indoors, which helps deliver better quality. I took some great shots in lesser light where the Galaxy S6 struggled, maintaining great color quality with little (if any) visible grain or artefacting.
Low light performance is still a weak point with most smartphone cameras, and that's the case with the Galaxy S7 too. However, performance in this area is improved compared to competing smartphones, and it is possible to get good images without using a flash. The S7 does have a habit of over-brightening scenes, occasionally to its detriment as it can select unnecessarily high ISOs, thus introducing grain, but at the same time this can be a bonus in some scenes.
Of the few complaints I have about the Galaxy S7 Edge's camera, one would be that most images are tinted towards the 'cold' end of the spectrum. The iPhone 6s, for example, shoots similar photos with a warmer tone, which can look more natural in wide sunlit shots. Under artificial light, the S7 can also lack the same level of contrast you get outdoors, although the camera is better in this regard than most other high-end smartphones.