Image Quality and Performance

The Moto X’s main processor is a dual-core Qualcomm Snapdragon S4 Pro clocked at 1.7 GHz. Spec-wise, this isn’t particularly impressive, especially with more high-end phones using the brawny Snapdragon 800 quad-core chip. That said, the phone is smooth and responsive in normal use, and doesn’t feel underpowered. It’s possible that more raw horsepower would goose the sluggish panorama mode and speed up the already-snappy HDR processing, but software optimization often plays a bigger role in responsiveness than underlying hardware these days. 

The Moto X's Snapdragon S4  is clocked at 1.7 GHz, and although it isn't one of the fastest  processors around, the phone feels snappy and responsive in normal use. 

The camera app takes a second to open from the icon, and opening it from the lock screen shortcut takes about half a second longer. With the Quick Capture gesture, the camera is ready in less than two seconds. It’s middle-of-the-pack in terms of start times. 

Shot-to-shot time is sluggish at around one second (though with HDR enabled, it’s about two seconds, which is respectable). Shutter lag, on the other hand, is minimal by phone standards -- not quite as quick as the fastest but better than many. Focus is neither remarkably quick nor irritatingly slow. The Moto X has usually settled on focus by the time you’ve got your composition lined up. It’s also notably accurate. We ran into relatively few focus errors during our testing.  

Daylight, Low ISO

In good light the Moto X captures plenty of detail with its 10MP sensor. Noise reduction smudges some low-contrast detail, but overall detail retention is respectable. 

Colors are a little less saturated than usual for a camera phone, particularly with HDR off, so it less “pop” than some users will be accustomed to. While that’s a matter of taste, no one will appreciate the Moto X’s color accuracy issues. Images have a magenta cast far more often than we’d like. In cloudy light, colors are cooler than ideal. While that’s fairly common in phones, the Moto X also sometimes renders colors over-warm in warm light. Apart from these whole-image issues, our review unit occasionally put a magenta tint in blue skies in one corner or another. This is probably a color shading issue that, like the decentering blur we often encounter in phones, can vary from one individual unit to the next.     

We also noticed a few instances of unusual stripes of aberrant color on high-detail patterns like bricks that is likely to be a side effect of the sensor’s unusual RGBC filter array. While worth noting, this was rare and won’t be a serious concern for most users.

The Moto X generally picks reasonable exposures in good light, but seems to have more trouble holding detail in bright parts of the scene than some of the competition. This may be a combination of limited dynamic range and a slight tendency towards overexposure.

ISO 160, 1/562 sec
In good light the Moto X delivers decent levels of detail and somewhat muted colors.
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We left the Moto X’s HDR mode set to “auto” for most of our testing (see the Features section for the rationale) and it frequently kicked in when shooting outdoors in good light. The penalty of an extra second in shot-to-shot time buys you improved dynamic range and richer (though not necessarily more accurate) colors. If you tend to shoot static subjects, it may even be worth forcing HDR on during daylight shooting. 

Our review sample’s lens delivered admirable sharpness across most of the frame, with just a hint of softness sometimes visible in the lower-right corner. There is no objectionable color fringing around high-contrast edges, thanks either to the lens or efficient software clean-up.

ISO 160, 1/649 sec
No HDR
ISO 160, 1/752 sec
HDR

These two photos above were taken seconds apart with HDR set to auto, but for some reason the Moto X shot the first in normal mode and then engaged HDR for the second. The dynamic range is improved in the HDR shot, but the more deeply saturated colors are actually the more dramatic difference.

ISO 160, 1/157 sec
In soft outdoor light, the Moto X can produce pleasant skin tones, though a bit yellower than is strictly accurate.
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ISO 160, 1/83 sec
Here see how the color balance runs cool in cloudy light, as well as bit of the Moto X’s tendency to overexpose portraits .
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ISO 160, 1/48 sec
This is a particularly bad example of the magenta cast that sometimes occurs. It's rarely this bad, but it surfaces too often.
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ISO 160, 1/2703 sec
At base ISO, noise in areas of dark plain tone is visible at 100% viewing but not objectionable.
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ISO 160, 1/360 sec
Repeating patterns can create color artifacts, but the problem is rare.
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ISO 160, 1/2273 sec
The Moto X blows highlights with regularity, and overexposes more than some the competitors. Its HDR mode (which didn’t kick in here) can help.
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Low Light, High ISO

The Moto X’s RGBC sensor has an unusually high base sensitivity of ISO 160, which is a full stop faster than much of the competition (and more than two stops faster than the iPhone 5s, with its low base ISO of 32). In practice, this means that the Moto X can hold to base ISO and faster shutter speeds at lower light levels than some of the competition, helping it avoid both elevated noise and motion blur from moving subjects. At higher sensitivities that advantage becomes fuzzier, but the Moto X turns in a respectable performance (by phone standards) through ISO 1600. Above that, image quality falls to pieces, but no more so than most of the competition.

Even so, the Moto X is not quite a low light master. It lacks optical image stabilization (OIS), an increasingly common feature that is a boon for photographing static subjects in low light. Its lens is also a half-stop slower than the best. Also, it tends to overexpose in low light (and there’s no exposure compensation in the native app). Apart from the highlight clipping and general bad look it produces, this also pushes the ISO higher than it needs to go. Careful use of the spot metering mode can offset this, but most phones don’t need that kind of handholding very often.

The Moto X tries to keep shutter speeds above 1/30 sec, which is good because without OIS, lower speeds invite shake-induced blur. In desperate cases it will drop as low as 1/12 sec, but the phone is very hard to hold steady enough for a clear shot at those speeds, especially without a hardware shutter button or even a "capture on release" onscreen button. 

ISO 160, 1/48 sec
The Moto X stays at its base ISO of 160 for this indoor shot. Detail looks good, though there are lots of blown highlights.
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ISO 320, 1/38 sec
The Moto X kicked into HDR mode for this image. Detail is good and noise is very controlled, possibly with the help of HDR image stacking.
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ISO 640, 1/50 sec
This night scene still looks good at screen resolution but zooming in reveals processing artifacts and an erosion of detail.
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ISO 1600, 1/17 sec
This dim indoor scene is overexposed. A lot of detail has been blurred away by noise reduction and some highlights are clipped.
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ISO 1600, 1/33 sec
This scene is overexposed. Sensor blooming (where overexposed areas “spill over” into adjacent pixels) and lens flare don’t help.
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ISO 3200, 1/14 sec
There is a lot of noise in this image much chroma blotching) but it is still adequate for web sharing. 
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ISO 640, 1/12 sec
This HDR image looks better than the one above, but other HDR shots taken of the same scene did not. Shutter speeds are also lowered, which increases the risk of blur.
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The Moto X has a bad habit of overexposing portraits of light-skinned people, a problem that’s exacerbated by the lower dynamic range of high-ISO shots -- the camera app doesn’t seem to use any kind of face detection, which would help avoid this. The solution is to turn on focus point selection, since exposure is then calculated narrowly from the focus area.

ISO 2000, 1/15 sec
Portrait normal
ISO 1600, 1/20 sec
Portrait with Spot Metering

Flash

The Moto X has a single LED flash, center-mounted next to the camera. It has the usual on/off/auto settings, and when left on auto mode it doesn’t kick in until the scene is very dim. There’s a pre-flash focus assist, so shots are usually in focus even in total darkness.

The flash is plenty bright for low-light portraits, but the resulting image quality is highly variable. Flash mode can produce nicely exposed shots with plenty of detail and pleasing color balance. But it might also yield soft, high ISO exposures, and/or weirdly desaturated colors when faced with the same scene. Your best bet is to check results or take several shots (though flash-dazzled subjects may not appreciate the latter strategy). On the plus side, the Moto X is very good at removing red eye, leaving only a barely-visible lightness at the center of pupils.

As you can see in the samples below the Moto X’s flash output is uneven. Given the same scene, the image can be very pleasant, marred by high ISO-softness, or badly desaturated.

ISO 2000, 1/20 sec
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ISO 1000, 1/48 sec
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ISO 1000, 1/48 sec
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