With the lowest compression, still photos generally weigh between 2.7MB and 4.7MB, which means they contain precisely the amount of information we'd want from such a high resolution image -- other phones are known to cap file-sizes at around 3MB, which hurts image quality.
The GS III also brings a multi-exposure HDR mode for bringing out more detail in highlights and shadows, and that works well. There's also a panorama mode for stitching together multiple shots to great one long horizon. Just like HDR, this is mode is extremely fast thanks to the processor. It's quick and easy to pull off little creative tricks.
The only thing missing here is real optical development: the maximum aperture is f/2.6, which is basically the same as its predecessors and well behind the light-loving f/2.0 lens on the HTC One X. This means the GS III will generally be worse off in low-light situations, although we still found that it performed admirably, with minimal noise. Also, compared to the excellent camera in the iPhone 4 (not 4S), the GS III may overexpose slightly and show less dynamic range -- its images are sharper and have more accurate colors, but at the expense of being less dramatic.
Moving on to video footage and it's clear that once again the snappy processor is living up to its rep: autofocus during video recording was some of the best we've seen in any smartphone. 1080p is recorded with a data-rate of around 2.2MB/s, which is very healthy indeed, and autoexposure shifts smoothly and sensibly. There's no slow-mo unfortunately, which counts against the GS III because that would have been a cool feature to have, but regular 1080p / 30fps footage is smooth and largely free of the rolling shutter "jello" effect.
Performance and battery life
So, we come to one of the GS III's not-so-secret weapons: its Exynos Quad processor, which is the only other engine beyond NVIDIA's Tegra 3 to bring more than two cores to a mainstream handset. If you need further evidence of just how bleeding-edge the new 1.4GHz quad-core Exynos is, you only need to look at its transistor size. Shrinking transistors is an expensive, painstaking business that only high-volume companies like Samsung can afford, but for the end user it broadly translates to a capacity for more performance with less battery drain -- yes, that's both at the same time; one of the physical world's rare win-win situations. The GS III's silicon is a fabricated with a 32-nanometer process, which is significantly smaller than last year's generation of 45nm phones and also smaller than Tegra 3's 40nm process. The only other mainstream mobile phone processors that benefit from such shrinkage are Intel's 32nm Medfield, which is put to good effect in the Lava Xolo for example, and Qualcomm's remarkable 28nm Snapdragon S4, which powers phones like the HTC One S and the LTE version of the HTC One X.
Okay, so what is this highfalutin Exynos chip capable of in real-world terms? Let's start with daily operation first: this phone boots up from cold in under 25 seconds and never stalls, never lags and never trips over itself. Whether you're navigating picture-heavy PDFs in Polaris Office, playing back chunky 1080p clips shot on your DSLR, or simply surfing content-heavy websites, you'll never even think about the processor. The true power of this processor will only materialize as the software becomes available to exploit four-way multi-threading. In the meantime, the only way you're going to test this phone is if you get the chance to do crazy things like running tough augmented reality apps (something we'd like to do in future, in order to test the graphical component of the Exynos), or a dual OS, or playing Skyrim, or if you run benchmarks.
Which brings us smoothly on to those (slightly) less subjective arbiters of performance. We've recently updated our suite of tests, so there are actually two sets of tables. The first, above, throws the GS III up against recently-reviewed phones using our new benchmarks. (Note: all the numbers for other phones come after recent firmware updates, so they might be different to what we've published in earlier reviews.)
On the whole you're looking at a device that is unsurpassed in terms of performance.
On the whole you're looking at a device that is unsurpassed in terms of performance. The GS III loses out to the One X on a few scores but beats it on others. It does particularly well on the SunSpider score, which reflects web-browsing performance: it's on a par with the One X here, and well beyond the latest Apple A5-based devices –- for instance, the new iPad only scores 2,011ms. If we look at Tegra 3 devices, like the global version of HTC One X, which isn't listed on the table above, we see a similar picture of the GS III winning on some and losing on a couple (namely CF-Bench and Quadrant). Overall, we'd have to call it a draw between the GS III and either variant of the HTC One X, at least on the basis of these specific tests.
Lastly, for the sake of comparison with a few older and cheaper devices, we've included above a legacy table with our previous suite of benchmarks. Although these benchmarks struggle to distinguish between the very latest phones -- which is precisely why we've moved on from them -– they nevertheless prove two things. Firstly, if processor grunt is a primary concern then you don't need to splash out on a GS III: you can do at least as well with a the Snapdragon S4-fueled HTC One S, which is a significantly cheaper handset. Secondly, the Galaxy Nexus – much as we love it -- is now very much last year's news in terms of horsepower.
Ah, but wait a second. We can't move without acknowledging that performance has a flip-side: battery drain. We had high hopes for the GS III in this regard, after we saw it had an unusually high-capacity 2,100mAh battery, and after GSMArena found in their own tests that the handset can go for almost as a long as a tablet. Fortunately, we can corroborate those results. Hooked up to Vodafone's HSPA+ network in London, UK, the phone survived a full day of intensive use. That included running energy-sapping benchmarks, shooting stills and video, web-browsing over WiFi and cellular data for over an hour, plus around 40 minutes of voice calls. (For the record, we had no problems with reception or audio quality, whether through the earpiece, speakerphone or the bundled canalphone headset -- although the latter was too tinny to be taken seriously for music.)
In our looped video battery run-down test, the phone lasted somewhere between 8.5 hours and 9.5 hours. This is a great result given the phone's screen size and resolution, and the fact that it only has a very early firmware version. It's also basically the same as the nine hours achieved by the AT&T HTC One X -- so close that we're going to re-run the test to get a more precise measurement and hopefully establish a clear winner. We'll update this review as soon as that's done, and also add more battery-life examples of everyday usage, but in the meantime, rest assured that this phone already scores extremely well for battery life.
Update: a second run of the looped video test yielded nine hours and two minutes. That's a brilliant score given the screen's size and resolution. Motorola's Droid RAZR Maxx might offer up more, but that phone is only qHD and its processor is relatively underpowered compared to the GS III's.
The GS III is an Android (Version 4) phone, but it has a very heavy TouchWiz skin stuck on top of it. This means that in addition to the typical Android-style clutter of widgets and menus and settings screens, the phone also has Samsung-only twists that add to a general sense of busyness. For fans of iOS (no widgets) or Windows Phone (no clutter), the whole thing might be a turn-off. Equally, if you're a devotee of the pure Android 4.0 user interface, which is more fluid and less busy than earlier versions, then you'll also be disappointed.