In addition to all these "quick" settings, you can jump into the camera-mode menu straight from the viewfinder. The options in here are similarly endless. There's Sony's "superior auto" mode, manual mode (you must use this if you want full 20.7-megapixel images), 4K video-recording mode, panorama, burst shot, background defocus, live-to-YouTube broadcasting, ad infinitum. New additions to this lineup include AR fun and effect modes, which let you pepper images with characters, objects and 3D text; Face in mode that creates a picture-in-picture image using both shooters; and Multi-camera mode, which stitches images from two paired Sony devices together. You can download even more, too, through a special store built into Sony's camera app. I'm sure most of these are useful in the right situation, and it means you can make the most out of the 20.7-megapixels you're given, but I find the app horribly cluttered due to the sheer number of modes and settings. I'm not saying the camera app should have fewer features, but there has to be a simpler, more user-friendly way of keeping them accessible without distracting from the primary camera functions.
I mentioned the dedicated, physical shutter key in the hardware section, but it's worth revisiting here. The two compression points (first to focus, second to shoot) are very clearly defined, and I preferred them to the on-screen shutter button (you can also bring up the camera app with a long-press of the physical key). Shutter response is near-instant, by the way, so you have a good chance of catching whatever shot you've scrambled to capture.
Now onto the primary camera's performance. Long story short, it takes some stunning pictures with perfect color saturation in well-lit conditions, whether you're in the manual mode taking advantage of every megapixel, or using the superior auto mode, which only takes up to 8-megapixel photos. In particular, some of the close-ups I took have an incredible level of detail, beating out one of Sony's NEX mirrorless digital cameras I happen to have. In favorable lighting conditions, the camera really excels, but it's not completely without fault. The automatic white balance setting is extremely accurate, especially when faced with artificial lighting. Occasionally, though, images came out slightly overexposed, meaning the auto-compensator hadn't judged the scene correctly. HDR mode didn't quite live up to my expectations either: It only adds a little extra "pop" to images.
Low-light performance is disappointing, and all the photos I took in dark conditions came out horribly noisy, with any light sources in the image appearing blown out. The Z3 and Z3 Compact are the only smartphones that currently support an ISO setting of 12,800 (only available in the superior auto mode), which is said to "take your smartphone to new levels of low light." The bigger the ISO value, the grainier you can expect an image to be, and yet my night shots were seriously noisy at ISO values under half that of the maximum 12,800. In manual mode, you can pick your ISO setting from 50 up to 3,200, but low-balling just results in crisper, pointlessly dark photos. Slow shutter speeds also mean you need to have an unnaturally steady hand to get anything other than a blurry mess. I'm not quite sure how Sony's managed it, but the Z3C's camera is fantastic in ideal conditions, and verging on terrible as soon as your available light fades. In some situations, you can use the LED flash to get a much better shot. It kicks out one hell of a blast, though, so anything too close will simply be an outline of white light.
Video performance is a similar story. On a bright day or in well-lit conditions, 1080p video at 30fps (it will also record at 60fps) has a lovely amount of detail. Not as good as stills, but almost. Recording moving subjects doesn't result in many dropped frames either, but the autofocus can be jumpy if you're panning around a lot. The Z3C is capable of recording 4K video too, which is gorgeous if slightly overexposed on the default setting. The audio quality here is also worth praising, but again, video performance falls off in poorly lit conditions -- clips become extremely noisy, and any light source looks like an explosion.(Full-resolution camera sample images are available here.)
Performance and battery life
A flagship name should come with flagship performance, which is something other "Mini Me" manufacturers don't take as seriously. Like the bigger Z3, the Compact uses a quad-core 2.5GHz Snapdragon 801, except it has 2GB of RAM instead of 3GB on the Z3. There's 16GB of internal storage -- just under 12GB of that is available to the user out of the box -- and a microSD slot ready to receive cards as large as 128GB. I shouldn't really need to tell you that a quad-core 2.5GHz processor is beyond adequate for everyday use. The phone flies when I'm navigating the home screen and menus, or hopping in and out of apps. Web browsing, too, is a delight, with everything loading as fast as your current connection will allow; no tiling or performance hiccups anywhere.
Gaming is a similar story. Throw a graphically intensive racer like Asphalt 8: Airborne at the Z3C, crank the graphics settings up to the max and you won't find anything to complain about. I expected as much from a Snapdragon 801, but it's still worth pointing out the Z3C is an absolute beast. Don't let its size fool you into thinking it's anything but a top-tier performer.
The Z3C supports basically every connection protocol there is. The GPS module locks on to your location almost instantly, and maintains a solid connection with accurate positioning; the handset also works with Russia's GLONASS and China's BeiDou GPS technologies. It also has every radio you could imagine -- dual-band 802.11ac WiFi, Bluetooth 4.0 LE, NFC, WiFi Direct, Miracast, MirrorLink, DLNA and MHL 3.0. There's also a Cat 4 LTE chip (maximum download speeds of 150 Mbps). Actually, if we're being precise, there are two variants of the device: The D5803 plays nice with LTE Bands 1, 2, 3, 4, 5, 7, 8, 13, 17, 20, while the D5833 supports Bands 1, 3, 5, 7, 8, 28 and TD LTE Band 40. That makes the D5833 the best SKU for Asian markets, and the D5803 the one European/North American buyers will want to spring for, but be aware that neither model is compatible with Sprint's LTE network.
The music-listening experience is far from an afterthought here, with high-resolution audio support and a "Digital Sound Enhancement Engine" that promises to upscale compressed files and improve their quality. Paired with Sony's now-standard ClearAudio+ tech, the Z3C makes for a solid portable music player. Songs have a clear, well-balanced tone when played through headphones, and you get an impressive amount of bass coming through, which is something a lot of smartphones struggle with. You'll never want for more volume than the handset can throw out, and if you purchase Sony's MDR-NC31EM headset, you'll also benefit from the phone's integrated digital noise-canceling tech. The stereo speakers on the front of the Z3C are no joke either. You can crank them up to 11 with minimal distortion, but you won't get quite the same depth of sound as you do through headphones.
The Z3 Compact runs on a non-removable 2,600mAh battery, which is a lot of juice for a phone this size, especially since a 720p display isn't as power-hungry as a higher-resolution panel would be. Sony could've slyly figured out cold fusion for all I know, though: The battery life is nothing shy of incredible. The company claims the Z3C has a "groundbreaking two-day battery," but I consider this a modest claim, and only true for power users. If your phone tends to sit on your desk at work for most of the day, with you checking the odd email, taking a few calls and doing a bit of farm maintenance in Hey Day, then you're looking at three to four full days of use without needing to recharge.
Considering every phone I've used in the past has, at most, made it through two days with relatively frugal use, I'm shocked at what Sony's managed to achieve here. The Z3C's battery life is simply outstanding, and that's without resorting to any of the several power-saving modes available. In Engadget's standard looping video test at 50 percent screen brightness, the Compact lasted an honorable 11 and a half hours before dying. That's only 45 minutes less than the Z3, which carries a much larger 3,100 mAh battery, and is a nod to what you can expect with everyday use.
As I've mentioned, if you're hunting for a smaller smartphone with flagship DNA, your options are extremely limited these days. The new iPhone 6 is obviously a direct competitor to the Z3 Compact, but really, your decision between the two is going to boil down to which platform you prefer: iOS or Android. While the iPhone 6 only has a slightly larger 4.7-inch display, it commands a significantly bigger overall footprint than the Z3C due to it being only 6.9mm thick (compared with the Compact's depth of 8.6mm), and thus needing to spread its internal components around. You also need to consider how important battery life is, as well as what you want out of your smartphone's camera.
In the Android space, there are really only three phones that come close to the size of the Z3 Compact. They are the HTC One mini 2, Samsung Galaxy S5 mini and the new Galaxy Alpha. Each has its own merits. The One mini 2 has a beautiful aluminum unibody design, but is bigger than the Z3C in every way despite having a smaller 4.5-inch 720p display. HTC's shrunken flagship also has a quad-core 1.2GHz Snapdragon 400 processor and 13-megapixel main camera, as well as a smaller 2,100mAh battery. The Galaxy S5 mini is both taller and thicker than the Z3 Compact, with a 4.5-inch 720p screen, quad-core 1.4GHz processor, 8MP camera and 2,100mAh battery. Some of the Galaxy S5's premium features have carried over to the smaller version, like waterproof certification, heart rate monitor and fingerprint scanner. The HTC One mini 2 is a lovely device, especially if you're not down with Sony's design ethos, but the problem with comparing these with the Z3C is that they simply aren't in the same league as the Compact when it comes to computing power and imaging.
Samsung's Galaxy Alpha is a stronger competitor. It's one of Samsung's best-looking handsets to date, and carries the same powerful processor as the Z3 Compact. It has a fingerprint scanner and heart rate sensor like the GS5 mini, as well as a 4.7-inch 720p display, but still isn't as impressive as the Z3 Compact is several areas. It only has a 12-megapixel camera, for example, no expandable storage and a fairly meager 1,860mAh battery. It's also much taller than the Z3 Compact, and thus isn't as neat. Furthermore, it's seriously expensive, at around $720 for an unlocked Galaxy Alpha.
No US carriers are currently ranging the Z3 Compact, leaving us raw, unlocked pricing to assess its competitiveness (UK pricing can be found here). Sony's recently started selling the Z3C in the US for $530 online, but Expansys currently has the best deal at $510. Newegg will sell you one for $520, GSM Nation for $529 and Amazon's price point tends to fluctuate within the $520/$530 range. Compared with the Galaxy Alpha, the Z3C is obviously the better option, but the HTC One mini 2 and Galaxy S5 mini do come in cheaper than the Compact. As a brief aside, a contract-free iPhone 6 is $649 from T-Mobile in the US, but again, they run different platforms, which I imagine will be the real deciding factor, not price. On Amazon, a One mini 2 retails for around $455, while the S5 mini (LTE version) goes for $430. Both are cheaper than the Z3 Compact, but I would say the $100 or so more you'd pay for Sony's pint-sized flagship is worth every cent, if only for the extra battery life. If you're not after top-of-the-range specs, though, the HTC One mini 2 is a striking device, even if it is bigger than the Compact.
Having spent a decent amount of time with the new Xperia Z3 Compact, I can easily recommend it as the best small Android smartphone. Low-light camera performance aside, it's got everything you want in a flagship handset, except maybe a fingerprint sensor or coffee maker, packed into a neat and portable package. Its rectangular design might not appeal to everyone, but it's an extremely well-built device with a certain understated elegance. You've also got yourself a great camera as long as conditions are favorable, and all the power you could possibly need with a quad-core 2.5GHz CPU at its heart.
The Z3C's endless battery life is truly something to behold, and compared with competing handsets of a similar size, it's reasonably priced, to boot. The reality is you don't have much choice if you're after a top-spec device that comes in under five inches, but Sony's shown once again that a smaller flagship doesn't necessarily need to be a lesser flagship.