Xiaomi's camera experience has improved quite a bit over the years, and the Mi MIX 3 represents the absolute best camera they've ever shipped on a phone. Sporting dual 12-megapixel sensors on the back and a pair of cameras on the front, the Mi MIX 3 features plenty of options for mobile photographers. The main rear sensor measures in at 1/2.55-inches with a pixel size of 1.4µm, featuring dual-pixel PDAF and 4-axis OIS, all behind an f/1.8 lens. The secondary rear sensor is a smaller 1/3.4-inch sensor without OIS and with smaller 1.0µm pixels behind a 2x-effective telephoto lens. On the front, under the slider, is a main 24-megapixel 1/2.8-inch sensor with a pixel size of 0.9µm, supported by a 2-megapixel depth sensor. Much of this configuration is shared with the Xiaomi Mi8 that was released a few months ago, and quite a bit of the Mi MIX 3's spec sheet is also shared with the Mi MIX 2S as well.
Despite having nearly identical hardware, the Mi MIX 3 delivers the best camera experience on any Xiaomi phone to date and produces generally excellent images in any light. The MIX 3's low light performance is, perhaps, its weakest point, but even this is well above average for the price point. Auto mode does a good job of quickly capturing dark scenes, pulling in more light to the scene than the human eye can see. Xiaomi's new Night Mode further helps with this, but it's not nearly as aggressive as other night modes and will generally produce a darker picture when compared to other phones with night modes in this price range, such as the OPPO R17 Pro or the HONOR View20.
Daytime performance is excellent and will give you great results in any situation. My biggest gripe was that Xiaomi's auto HDR isn't nearly as aggressive as I'd have liked, which resulted in a few photos where parts of the image were underexposed. This due to the exposure bias choosing to balance the bright sky rather than focus on the darker elements in the scene. A more aggressive auto HDR would have resolved this, as evidenced by choosing to force enable HDR at all times. The biggest advantage that appears to come from a less aggressive auto HDR mode is in motion capture, which manifests itself in crisp, clean imagery of pets, children and other moving subjects that can sometimes be blurry on other phones.
Xiaomi also seems to prioritize shutter speed over ISO, meaning that it'll crank up the ISO levels in lower light environments before it raises shutter speed. This helps remove hand jitter and, again, helps with subjects that are moving since the shutter isn't staying open for a lengthy amount of time to bring more light into the scene. Telephoto performance is also good, with a proper 2x zoom-style telephoto lens to enable better quality when zooming into subjects. This is a higher f-stop rated lens, so low light performance won't be quite as bright and crisp as photos taken with the main sensor.
Xiaomi's video recording abilities are nothing short of amazing in every regard and represent some of the most capable in the industry. Support for recording up to 4K resolution at 60FPS with OIS and EIS are available, h.264 and h.265 compatibility, time-lapse support up to 60-second intervals between shots, and even slow-motion capability in 1080P resolution up to 960FPS speed. Xiaomi's implementation of slow motion is unique as well; hitting the record button will produce a 10-second 960FPS super slow-motion video with a 3-second lead-up to the slow-motion movement.
Unfortunately, like Huawei's implementation, there's a 5-6 second processing time after the phone records the slow-motion session, meaning that if you miss the moment by a fraction of a second, it's going to take nearly 10 seconds to get another try at recording that moment again. This slow nature extends to the overall design of the interface which has, unfortunately, moved to the iPhone-style horizontal carousel of mode names sprawled across the bottom of the screen, forcing users to slowly move their way through the carousel by swiping left or right until the desired mode is selected. Having all modes in a single place is a better design, and it's disappointing to see Xiaomi move away from that design just to fit in with the poor decisions most other OEMs have made.
Fans of selfies and portrait mode shots will be quite happy with Xiaomi's implementation on the Mi MIX 3. The 24-megapixel front-facing camera is a higher resolution than most on the market and delivers consistently good results, no matter the lighting condition. Portrait mode shots from this camera are generally good, thanks to the dedicated 2-megapixel depth sensor whose sole job is to detect the distance between objects and apply appropriate blurring to the background. Likewise, the rear-facing camera will utilize that secondary camera as the main portrait shooter, while the main sensor works as a depth sensor.
Both front and rear-facing camera portrait shots can have their blur amounts and styles adjusted after taking the shot, and Xiaomi's tools for this job are particularly impressive. It's not just the amount of background blurring that can be adjusted, but also the type of lighting, including some gnarly new effects like "blinds" or "dots" which make the appearance of light being cast across faces in the shot. You can adjust the angle this light comes in from, as well as animate the blurred backgrounds for greater effect. It's definitely cool, and will certainly appeal greatly to a specific crowd.
Battery, Performance, Sound, and MIUI
While it's clear Xiaomi didn't spend an inordinate amount of time focusing on the sound output for the Mi MIX 3, that doesn't mean it's necessarily a weak point of the phone. There's no 3.5mm audio jack on this device, but it ships with a USB Type-C to 3.5mm adapter, and of course supports Bluetooth 5.0 with the highest quality codecs available. It's also got a capable bottom-facing speaker that can deliver good enough sound for watching videos or playing a quick tune when a better external speaker isn't available.
On the surface, it may not seem like Xiaomi has left much room for a reasonably sized battery inside the Mi MIX 3, but the opposite is, thankfully, the truth. A rather large 3,850mAh battery has been placed inside, and while it doesn't feature any cutting-edge ultra-fast charging functionality, it still supports Qualcomm's QuickCharge standards as well as 10W fast wireless charging. Xiaomi includes a wireless charging puck with every Mi MIX 3, something unheard of in the industry, especially for a phone that sells for cheaper than every other flagship in its class.
Battery life as a whole is excellent, part of which is owed to that large battery, and part is due to a smart mashup of hardware and software design. An OLED display helps conserve power while providing superior image quality to LCD panels, and Qualcomm's Snapdragon 845 is an efficient, yet powerful chipset found in every 2018 flagship phone. You'll never want for more performance, of that there's no doubt, no matter what's done on the phone. A choice of 6GB, 8GB, or 10GB of RAM means that multitasking is as good as any modern smartphone can get, but there's one big area that constantly caused me headaches during the review period: "battery saving" features of the OS.
We've seen this problem on plenty of Android phones out there, something that we had hoped would go away when Google began introducing features like Adaptive Battery in Android 9 Pie. Unfortunately, the opposite seems to have come true, and we've seen more similar issues on more phones than ever. It's an incredibly frustrating experience because it means, in the simplest of terms, that you're likely to miss notifications for apps that you use if these "features" aren't turned off. MIUI works to keep apps from needlessly running in the background, but it feels more like the OS is needlessly killing off an app's effectiveness to deliver timely notifications instead.
I also had some bizarre issues with app notifications that were not power-related. For instance, Google's Messages app refused to make any sort of sound or vibration when an SMS or MMS text message would come in. A notification would display in the notification shade, but never a pop-down message, no audible sound, and no physical vibration of the phone. This particular issue seemed to only happen with that app, but I had plenty of times where the phone would do this with all notifications after silent mode was toggled off, as if silent mode would bug out and get stuck on despite the phone saying otherwise. A simple restart always fixed it, but it was an incredibly irritating problem to have happen. We've been working with the MIUI team directly on this issue and hope it will be resolved in the near future.
MIUI 10, Xiaomi's own version of Android, runs atop a custom-tailored version of Android 9 Pie. Utilizing its own style that's wholly unique among Android vendors, Xiaomi has taken the best aspects of Android 9 Pie and run with the concepts, all while seemingly removing all of the negative aspects. The visual design here is gorgeous and looks straight out of an artist's rendering of what a modern UI should look like. It almost feels as if Xiaomi took what Google couldn't quite get right and simply fixed it up into a beautiful, cohesive experience across the board.
Full theme support means theme authors can completely customize the look of the UI. This includes every single element you see on screen, bar none. The best themes include full UI refreshes, with custom imagery all throughout, and themes that may render MIUI 10 unrecognizable from its stock look and feel. Don't care for Xiaomi's latest bright style? Maybe a simple dark theme will do it for you. Want a seasonal theme that matches this month's color scheme instead? You're sure to find it on this huge marketplace, and it's not only simple to search for what you want but even easier to manage and customize each one to your liking.
MIUI has always been one of the most feature-rich versions of Android on the market, and while Xiaomi's famed weekly updates don't appear to be alive and well on this particular Global version of the phone, Xiaomi's update schedule is better than most OEMs by a long shot. MIUI also provides an incredible amount of security-related features, from a super granular permissions structure that allows sorting of apps by allowed permissions, to the ability to hide apps behind a second biometric layer of authentication, or even cloning apps to more efficiently run multiple accounts.
Xiaomi is once again showing the world that stunning design and build quality doesn't have to cost an arm and a leg, and it doesn't need to water down the experience to achieve greatness. This is Xiaomi's most impressive phone to date, without a doubt, and that's saying quite a bit given how regularly the OEM delivers on the promise of a quality device without the high price. The Mi MIX 3 is unparalleled in its look and feel and delivers a wholly unique design that provides yet another compelling alternative look at how bezels make up a modern smartphone without compromising on features that users want and need, like a front-facing camera, for instance.
MIUI 10 based on Android 9 Pie is the sleekest version of MIUI yet, and it pulls off a brand new and gorgeous design without removing important features or cutting back on ways to customize the experience. Xiaomi's excellent full-screen gestures make the bezel-less design even more immersive, and their new multitasking Recents/Overview screen layout is a significantly better design than most other phones powered by Android 9 Pie, particularly for folks who find themselves juggling multiple apps throughout the day. It's also a workhorse in every respect, from processing power to the ability to buy a model with up to 10GB of RAM, and even to the fantastic battery life and convenience of wireless charging out of the box.
Even the camera experience is above average in the price range, offering quality you can count on in any light, and a slew of new features that are well worth looking into. Night mode, new portrait mode lighting effects, and a faster, more efficient back-end round out high-end camera hardware. It's a solid value from a company that consistently delivers solid value devices, and one that doesn't feel like it suffers from "me-too" syndrome, as so many other smartphones on the market do; Xiaomi's own lineup included.