Studio scene in low light

In this low light scenario the 5s' image quality is again very close to its predecessor, the iPhone 5. Noise reduction is taking a huge toll on fine detail but both luminance and chroma noise are very well under control.

Like on previous iPhones Apple has found a very good compromise between noise and detail retention but it's worth pointing out that the improvements over the iPhone 5 are very marginal. At a shutter speed of 1/15th sec and without optical image stabilization camera shake is also a real danger.

Although both the iPhone 5 and 5s have chosen the same shutter speed of 1/15s, the 5s is selecting a significantly lower ISO of 320. Even though the new lens on the 5s is 1/3 (f/2.2) stop brighter than the iPhone 5 (f/2.4), the 5s has also exposed the scene about 2/3 of a stop darker, which makes up for the majority of the discrepancy between the cameras. 

Overall the 5s performs well in our low light scene, producing a clean image that shows similar or even better detail levels to the competition with higher resolution conventional sensors such as the Samsung Galaxy S4 but it cannot keep up with the Nokia Lumia 1020 and its much larger 1/1.5 inch sensor.