One of our favorite travel photogs, Austin Mann, snapped up an iPhone 5 and flew to Iceland last year in order to pit Apple's latest flagship against its prior king in a bitterly cold camera test. This year, Mr. Mann hopped a flight down to Patagonia in order to pit the iPhone 5s' sensor against that of the 5. One of the more remarkable findings was the dynamic exposure applied to panoramas with the 5s; in his testing, pans that involved dark and light subjects were accounted for properly without the use of HDR. The result was a far more evenly lit panoramic image, whereas prior iPhone cameras tended to blow out a portion of the image to compensate for another portion.
The 5s also demonstrated dynamic range that was said to be "remarkably better" than on the 5. In post-processing, images taken with the 5s maintained integrity far better than the 5 when using Snapseed to recover details lost in shadows. Not surprisingly, shutter lag has gone from impressive to "nonexistent," and he noted that the 5s' burst mode is intensely useful for action shooters who need to quickly grab a litany of shots (say, of a lion pouncing on its next meal) and select the one with just a few swipes.
The iPhone 5's camera was certainly no slouch, but Apple's tweaking seems to have produced a markedly superior camera on the 5s. Interestingly, in a gallery of side-by-side comparison shots, the 5s displayed results that were a bit flatter with less noticeable contrast. According to Mann, "photographers will liken this to a RAW image, which doesn't look as nice off the bat, but has a lot more flexibility for editing on the backend." For more comparisons -- including a look at the 120FPS Slo Mo mode -- point your browser of choice right here.