Portrait (Low Light)

This portrait was shot hand-held in a dimly lit room with all systems on Auto mode.

 Samsung Galaxy S4, ISO 800, 1/30 sec
Apple iPhone 5, ISO 400,1/17 sec
HTC One, ISO 244, 1/20 sec
 Nokia Lumia 920, ISO 400, 1/22 sec

All cameras do a decent job from an exposure point of view, although you'll see differences in color rendition and selected sensitivity settings. With its fast lens and optical image stabilization the HTC One can allow itself to keep the ISO low and use a slow shutter speed of 1/20 sec (the latter only works with non-moving subjects though). The Galaxy S4 has picked the highest ISO at 800 to compensate for its slightly slower lens, but also to achieve a faster shutter speed of 1/30 sec.

Both the Apple and Nokia have opted for ISO 400, but thanks to its faster lens and slightly darker exposure the Lumia 920 achieves a faster shutters speed than the iPhone 5. The latter's 1/17 second shutter speed is borderline for any live subject and some of the softness in the image can probably be attributed to very slight subject movement.

 Samsung Galaxy S4, 100% crop
 Apple iPhone 5 100% crop
HTC One, 100% crop
 Nokia Lumia 920, 100% crop

Noise reduction is showing its ugly face on all of these shots. None of the cameras here are capable of preserving a lot of fine detail, but the Nokia captures the most detail in this low light situation by taking advantage of optical image stabilization and keeping the ISO relatively low.

The Samsung, HTC and Apple images all look very soft at a pixel level. At ISO 244 noise is still pretty well controlled on the HTC. The Samsung has shown almost no chroma noise but some unpleasant noise reduction artifacts, while the iPhone image is grainier and shows more chroma noise than the rest in the shadow areas.

Portrait (Flash)

With their tiny LED-flashes flash performance tends to be one of the weak points of all smartphone cameras. We've tested the feature hand-held in our darkened studio, with flash and all other settings in Auto mode.

 Samsung Galaxy S4, ISO 200, 1/30 sec
Apple iPhone 5, ISO 400, 1/16 sec
HTC One, ISO 102, 1/40 sec
 Nokia Lumia 920, ISO 800, 1/25 sec

The Nokia Lumia produces the most balanced flash exposure, with a well-illuminated subject but avoiding blown-out highlight on the subject's skin. The HTC has again produced a darker exposure than the rest while the iPhone 5 overexposes the subject significantly.

Samsung Galaxy S4, 100% crop
Apple iPhone 5, 100% crop
HTC One, 100% crop
Nokia Lumia 920, 100% crop

The Samsung Galaxy S4 can keep the ISO down to 200 which in combination with the 13MP sensor means it captures the best detail in this comparison. The HTC is capturing the image at base ISO but that's stil not good enough to rival the Samsung in terms of image detail. The Nokia's decision to select ISO 800 for this flash shot means it trails behind the competition in terms of fine detail.

The red-eye effect is very pronounced on the iPhone 5 and just visible on the Nokia but well under control on the Samsung and HTC One.

Night Scene

We've also included a night scene in our comparison. All shots were taken within minutes of each other, so the light conditions were almost identical. Devices were mounted on a tripod using the iStabilizer mount and set to Auto mode. We did not engage Night or HDR modes that are available on some of the phones. However, those are and will be covered in the individual reviews.

Samsung Galaxy S4, ISO 2000, 1/30 sec
Apple iPhone 5, ISO 800, 1/15 sec
HTC One, ISO 564, 1/15 sec
Nokia Lumia 920, ISO 640

As you can see in the samples above, the cameras' approach to exposure varies quite a lot for this scene. The Galaxy S4 does not appear to select slower shutter speeds than 1/30 sec in its standard mode which requires it to push the ISO up to 2000. Yet, the image still looks a little underexposed. The iPhone produces a very underexposed image at ISO 800. Yet the shutter speed is only 1/15 sec which would be very slow for a hand-held capture. The only way to push the exposure up is by trying to tap-focus on a part of the screen, the results of which can be seen below.

The HTC One arguably achieves the best balances exposure in this night shot comparison and does so by keeping the ISO down to 564. Its shutter speed of 1/15 would, thanks to the optical image stabilization, be more feasible for hand-held capture than on the iPhone. The Nokia takes a totally different approach and applies an HDR-type effect to the image, which results in a slightly unnatural look. There does not appear to be an option to disable this effect.

 Samsung Galaxy S4, 100% crop
Apple iPhone 5, 100% crop
HTC One, 100% crop
 Nokia Lumia 920, 100% crop

It's a little difficult to directly compare these crops as the cameras have produced such different exposures, but it's fair to say that the HTC One produces the best balance of low ISO, noise reduction and noise. Of course you have a much small image to start with than on the Samsung or Apple. If you are happy to do some clever editing on the latter files, you might be able to achieve similar 4MP results as on the HTC. However, it's probably fair to assume that most smartphone users would not want to put that much effort into their images.

Despite the relatively low ISO the Nokia image is very soft with absolutely no fine detail left in the scene. If you like the color rendition you might be able to live with this at smaller viewing sizes, but it's not pretty close up. Given it has selected by far the highest sensitivity it's no surprise the Galaxy S4's image is the noisiest here but at equalized viewing sizes the difference is less noticeable.

iPhone 5, ISO 2000, 1/15 sec: For this sample we tried to push the iPhone's exposure by focusing on a dark part of the scene. This pushes the ISO to 2000 and results in a very soft image. The latter is probably attributable to both the high sensitivity and the AF struggling with the low contrast in the shadow areas. We took a range of images, focusing on different image areas. This is the best.