Indoor Scene

This shot was captured inside a library at night, with all lighting provided by fluorescent lamps.  Despite the building interior being well lit, the light levels are much lower than outdoors on a bright day and all cameras increased the ISO setting accordingly. The HTC, Samsung and the Sony in Manual mode did so relatively moderately and opted for slow shutter speeds that increase the risk of camera shake. In its Auto mode, the Xperia Z1 is the only camera to opt for a higher sensitivity of ISO 640 and therefore a faster shutter speed of 1/64 sec. 

Despite that none of our test models have an optical image stabilization system, with the wide-angle of view of the lenses, the chance of image blur through camera shake are still pretty low at shutter speeds around 1/15 sec. If you take two or three images the odds of having at least one sharp exposure are pretty good.

All cameras handle  white balance pretty well, capturing fairly neutral results, but again the Sony is a little cooler than the Samsung and HTC. As we've seen before, the HTC delivers a slightly darker exposure than the other phones and the Samsung is the brightest.

Sony Xperia Z1 Compact - 20.7MP
ISO 320, 1/32 sec
Samsung Galaxy S4 Mini
ISO 250, 1/17 sec
Sony Xperia Z1 Compact - 8MP
ISO 640, 1/64 sec
HTC One Mini
ISO 200, 1/33 sec

When zooming in to 100% we can see that all phones are still doing pretty well in this low, indoor light. Some noise is visible in all pictures but it's almost exclusively luminance noise (grain) while color noise is well controlled. At ISO 200 the HTC uses the lowest ISO and delivers a pretty clean image albeit with less detail than the others. It's also the only device that shows some visible purple fringing around some of the light sources in the image. On the upside it shows less chroma noise than we can see in the blue sky of our HTC sunlight sample.

Thanks to the extra pixels, the Sony's 20MP mode still shows the most detail in this shot but the 8MP Sony and Samsung are not far behind.

Sony Xperia Z1 Compact - 20.7MP
100% crop
Samsung Galaxy S4 Mini
100% crop
Sony Xperia Z1 Compact - 8MP
100% crop
HTC One Mini
100% crop

Night Scene

This night scene was captured during the blue hour, just before the sky turned really dark. Light levels are much lower than in the previous samples and all cameras have to crank up the ISO to achieve a manageable shutter speed. In its Manual mode the Sony caps ISO at 400 which leads to very slow shutter speeds of 1/13 sec. In its 8MP Auto mode the camera goes higher, to ISO 800, and therefore can speed up the shutter to 1/25 sec. Due to its slower F2.6 aperture the Samsung has to go up to ISO 1000 for 1/17 sec and the HTC keeps the sensitivity lowest at ISO 500.

Again there are minor differences in exposure and color response between the devices, but overall all three smartphones are doing a decent job. It's noticeable though that the Samsung has a little trouble with bright light sources in otherwise darker scenes. The area of the fluorescent tubes underneath the station roof looks very hazy. The same effect, albeit less pronounced, was visible in the indoor shot above.

Sony Xperia Z1 Compact - 20.7MP
ISO 400, 1/13 sec
Samsung Galaxy S4 Mini
ISO 1000, 1/17 sec
Sony Xperia Z1 Compact - 8MP
ISO 800, 1/25 sec
HTC One Mini
ISO 500, 1/14 sec

Close-up we can see the effects caused by different shutter speeds and ISOs. The Samsung is clearly the noisiest image in this comparison. Strong noise reduction creates unsightly noise blotches and an overall soft image. The HTC can catch a little up with the competition in these low light conditions, but its output is still not great. Like the Samsung it shows a lot of noise and softness caused by noise reduction at the same time.         

Sony Xperia Z1 Compact - 20.7MP
100% crop
Samsung Galaxy S4 Mini
100% crop
Sony Xperia Z1 Compact - 8MP
100% crop
HTC One Mini
100% crop

There is a lot of luminance noise in the Sony's 20MP image too, but it has not been "blotched" by noise reduction, making it appear less intrusive than on the Samsung or HTC. The Sony's problem is that in Manual mode Auto ISO does not go any higher than 400 and a shutter speed of 1/13 sec is not fast enough to capture an image that is sharp at pixel level. We took about ten pictures of this scene with the Xperia Z1 Compact in its 20MP mode, all of which were soft to varying degrees. We have picked the best one for this comparison.

Overall the best image of the night scene was captured by the Sony Xperia Z1's 8MP Auto mode. It's grainy but not excessively so and noise reduction is still at acceptable levels. Chroma noise is very well controlled and the image is sharp with comparatively good detail.

Samsung Galaxy Night Mode
no Exif-data available
HTC One Mini Night Mode
ISO 500, 1/14 sec

Both the Samsung and HTC also offer a Night Mode than can be selected in the camera menu. The Samsung stacks a couple of exposures in order to average out the noise which requires a few seconds of processing after the shot has been taken. The resulting image is a lot cleaner than the one taken in standard mode but also very soft. On the HTC it's not quite clear what the mode actually does. Apart from minor color differences the Night Mode image is identical to standard mode, including shutter speed and ISO. We have posted the Night Mode samples above for you to check out.

Flash

For this test we set the flash on all devices to Auto mode and shot in an almost dark room. As you can see in the sample images below the results vary quite a lot. In terms of exposure, the Sony is a little brighter than the Samsung and the HTC has produced the darkest image by far. All devices avoid the cool color response which used to be typical for flash pictures of previous smartphone generations. Overall we like the Samsung's exposure and contrast best in this comparison, closely followed by the Sony. The HTC simply is too dark for our taste.

Sony Xperia Z1 Compact - 20.7MP
ISO 500, 1/32 sec
Samsung Galaxy S4 Mini
ISO 125, 1/21 sec
Sony Xperia Z1 Compact - 8MP
ISO 1000, 1/64 sec
HTC One Mini
ISO 125, 1/44 sec

Examining the images close-up shows that, thanks to shooting at a low ISO, the Samsung has captured the best detail, but despite the higher sensitivity the Sony is doing a decent job as well. The HTC is again looking pretty awful. This is not only due to the very strong noise reduction that is applied even at base ISO but also the One Mini's troubles with focusing in very low light.

It's the only smartphone in this test, and in fact the only smartphone we have seen in a while, that does not use its flash LED as a focus light. As a consequence focusing in very low light can take a few seconds and even with a focus lock confirmed your subject is likely not totally in focus. The image we have picked for inclusion here was the best in a series of five.

Sony Xperia Z1 Compact - 20.7MP
100% crop
Samsung Galaxy S4 Mini
100% crop
Sony Xperia Z1 Compact - 8MP
100% crop
HTC One Mini
ISO 500, 1/14 sec

The HTC also shows the strongest red-eye effect. It's visible on the Samsung and in the Sony's Manual mode too, but to a lesser degree.  Overall it's fair to say that you are probably best off avoiding the use of flash on any of the devices in this comparison as the results are inferior to even cheap compact cameras. If you really think you want to take flash pictures with a smartphones on a regular basis your best bet is a model with Xenon-flash, such as Nokia's Lumia 1020. 

Conclusion

Picking a winner in a camera comparison can be a daunting task but not in this shootout. In terms of image quality the Sony Xperia Z1 is leading the pack in almost all areas. It might not be perfect, but it delivers decent detail in good light and offers a good balance between noise reduction and detail at higher ISOs. We also liked the natural colors and reliable exposure. As a bonus you get to choose between the 20.7Mp files, which can be useful for cropping, and the downsampled 8MP files which are a touch cleaner and more manageable when uploading to social networks and image sharing sites.   

In this test we are concentrating on camera performance but I have used all three phones as my main personal device for a few days and it's fair to say that the Sony is also the nicest phone among the three. Its build quality is excellent, the waterproof body is useful in adverse weather conditions and the fast CPU ensures smooth operation of OS and apps alike. The physical shutter button will be especially appreciated by mobile photographers.

In a comparison with the S4 Mini and HTC One Mini, the Z1 Compact's only downside is its price which at currently $525 off-contract is over $100 more than the HTC and $200 more than the Samsung. Nevertheless, if you want a compact smartphone that is not an iPhone, the Xperia Z1 Compact is an easy recommendation.

At  currently $320 off-contract, the Samsung Galaxy S4 Mini is an affordable alternative but can't keep up with the Sony in terms of image quality. While its metering system works reliably we found the color response a touch too warm and a mix of noise and strong noise reduction make close-up viewing of high-ISO output an unpleasant task.  The Samsung did well in our flash test though. The S4 Mini's lower price point is also reflected in the lower resolution screen and the slower Snapdragon 400 CPU which leads to a noticeably more sluggish overall performance than the Sony.

The HTC One Mini on the other hand offers a 720p screen and metal body which makes it look and feel like a premium device. Unfortunately the One Mini is let down by its camera. It delivers significantly less detail than the Sony and Samsung in all shooting situations, its lens has soft spots, it tends to produce purple fringing on high-contrast edges and the exposure often is a little darker than we would like. The fact that it's not using the flash LED as a focus light means that it has trouble focusing in very low light as well. It's fair to say that HTC's "Ultrapixels" have not been much more than a marketing term and we can't really recommend the One Mini to users who care about image quality.  We hope that the forthcoming One M8, HTC's new flagship device, will be capable of producing better image results.

If you're in the market for a compact smartphone but the Sony is too expensive for your budget and don't feel attracted to the Samsung or HTC either, you might want to wait a little longer for the LG G2 Mini which was announced during the Mobile World Congress in Barcelona. LG's compact model will feature an 8MP camera in most markets and come with many of the original G2's imaging features. We are planning to have a closer look at the G2 Mini as soon as we get a sample unit in our hands.