Camera, Display and Audio Quality
The Mi4 uses a JDI 5-inch 1080p IPS display and it’s excellent. Xiaomi claim it’s a high-saturation display capable of covering 84% of the NTSC colour gamut. It’s well calibrated and we have no complaints about quality. Viewing angles are good, as is outdoor brightness and colour reproduction.
The same goes for audio quality. Xiaomi doesn’t mess around in the audio department, so the earpiece and side-firing speaker are top notch. The phone also has a secondary noise-cancelling microphone on the back. Call quality is above average, along with earpiece loudness and clarity.
Both cameras on the Mi4 are based on Sony sensors, and by now you are probably familiar with the main camera sensor. The Sony IMX214 is used in hundreds of different phone designs, and it’s not the latest or most powerful sensor on the market.
The good news is that Xiaomi made the most out of it, with excellent f/1.8 optics. The fast aperture allows the camera to capture excellent images and deliver fast HDR performance.
We were not disappointed with the sample shots.
Indoor daylight shots were quite good, although a tad on the soft side. At night, sans flash, it's more of the same; good results with a bit too much softness on default settings.
The camera also supports a range of different modes, including manual controls, rapid fire HDR (10 shots per second), with hardware-based HDR preview. Users can choose between two very different HDR modes. The Pro mode is more or less a standard HDR implementation, while the other relies on different light balancing. The results are very different: the standard HDR mode boosts contrast and saturation, while the second one generates a much more realistic photo (note the haze in our sample shot).
As for HDR speed and ghosting, we can report that HDR is very fast and there's no ghosting in most situations, as our 100% crop illustrates.
The camera captures a lot of detail, despite the soft feel. Unfortunately, our model wasn't willing to pose, but you get the picture.
The MIUI camera app is feature-packed and intuitive, and it’s fast as hell. The Mi4 can even capture 4K video, although this is more or less pointless on a 16GB device.
The front facing camera is an 8-megapixel affair. Like the main camera, it features high-speed f/1.8 optics and does not disappoint. It can deliver some great selfies, even in low-light situations.
While a glance at the spec sheet may lead some users to conclude that the Mi4 camera is past its prime, this isn’t exactly true. A lot of cheap phones ship with IMX214-based cameras, but in most cases they feature cheap optics, so they don’t come close to the Mi4 in terms of image quality.