Landscape

This shot was taken on a bright but overcast day. As you can see in the samples below, in terms of exposure the Sony and LG are pretty close but the Samsung S4 Zoom has produced a visibly brighter image, the Sony a slightly darker one. The Nokia produces the warmest color response, the LG G2 the coolest. The Sony and Samsung fall in between. The image processing on all four devices is pretty punchy with strong contrast and saturation without crossing the line to looking unnatural.

Sony Xperia Z1, ISO 50, 1/800 sec, 20.7MP
Nokia Lumia 1020, ISO 100, 1/719 sec, 38MP
LG G2, ISO 100, 1/377 sec, 13MP
Samsung S4 Zoom, ISO 100, 1/400 sec, 16MP

Looking at the 100% crops it is clear that the Nokia Lumia 1020 with its 1-inch sensor captures more detail in good light than the competition. The Sony's 20.7 MP sensor captures a lot of detail as well, but close-up the image looks over-processed, with too much sharpening and processing artifacts. Both images show some luminance noise, even at base ISO.

The LG G2 performs pretty much as we would expect from a 13MP smartphone sensor. Low-contrast detail such as the distant foliage in our image is being smeared by noise reduction, but you only really notice at a 100% view. Despite having a larger sensor than the LG, the Samsung image is the softest in this comparison and it appears the 10x zoom lens on our test unit is slightly soft at the wide angle setting.

Sony Xperia Z1, 100% crop
Nokia Lumia 1020, 100% crop
LG G2 crop, 100% crop
Samsung Galaxy S4 Zoom , 100% crop

The Nokia Lumia 1020 delivers the best image quality in this test, with excellent fine detail and good exposure. The color response is a little on the warm side but overall in its 38MP image mode the Nokia is ahead of the other devices in good light.

Night Scene

Like the landscape tests above, in this night scene the Samsung Galaxy S4 Zoom produces a slightly brighter exposure than the rest of the field. And again the Nokia Lumia 1020's white balance produces the warmest color response, the LG the coolest. The Nokia image is also very saturated and while that gives it a vibrant look, it's also a little overprocessed.

Sony Xperia Z1, ISO 400, 1/10 sec, 20.7MP
Nokia Lumia 1020, ISO 800, 1/9 sec, 38MP
LG G2, ISO 800, 1/15 sec, 13MP
Samsung Galaxy S4 Zoom, ISO 500, 1/6 sec, 16MP

A look at the Exif data of our sample images reveals that in their auto modes all devices are aiming to keep the ISO as low as possible and therefore capture at shutter speeds that are, despite optical image stabilization systems on the Nokia, LG and Samsung, on the verge of being too slow for hand-held shooting. We shot a series of images with each phone and only found one or two really sharp ones from each device when we sifted through the results on our computer screen. 

The Nokia produces the cleanest image in this comparison but with its super-high resolution sensor, at a shutter speed of 1/9th second it is virtually impossible to capture an image that looks sharp at a 100% magnification, despite the 1020's fairly efficient optical image stabilization. It would make more sense for the auto ISO function to select a higher setting and trade some image cleanliness for sharpness.

Thanks to the lower sensor resolution on the other devices optical image stabilization performance is not quite as essential as on the Nokia. The Samsung and Nokia images are sharper but blighted by luminance noise (grain) and the effects of noise reduction. Especially on the LG at ISO 800 low-contrast detail is pretty much non-existent. Chromatic noise is well under control on all devices though.  

Sony Xperia Z1, 100% crop
Nokia Lumia 1020, 100% crop
LG G2 crop, 100% crop
Samsung Galaxy S4 Zoom , 100% crop

It's hard to pick a winner here. The Nokia Lumia 1020 is again capable of the best results if you're lucky enough to get a sharp image, or are willing to set the ISO manually for faster shutter speeds.  Of the remaining three devices the Samsung arguably offers the best compromise between noise and detail. The Sony still shows acceptable detail at ISO 400 but the image is very noisy and full of processing artifacts. The LG on the other hand is soft with very strong noise reduction applied which leads to a loss of almost all fine detail.