According to Apple the iPhone 5S camera is this good (below). That new 8MP iSight camera gives you a 15 per cent larger sensor than the iPhone 5. But how does it get better without more pixels?
Bigger sensor nodes. Which means bigger pixels - in this case 1.5 microns (compared to the Nokia Lumia 1020's 1.1 microns). And the bigger, the better.
So in the case of this flower you can see immense detail both in depth and colour range.
It also uses an f/2.2 lens to offer brighter images than the f/2.4 iPhone 5 lens could manage. So here even pointed into direct sunlight you can still clearly make out the plants in the foreground.
The dual flash is also a factor as this creates warmer amber light or cooler blue light for the phone to auto-select. So our jellyfish friend here comes out looking balanced with the colder and warmer ends of the light range clearly defined.
Auto image stabilisation lets the phone take multiple shots and combines them for exposure to pick the sharpest for the final image. The result is action shots, like this skateboarder, looking clear and defined while in motion. It's not a proper optical stabilisation system like on the Nokia Lumia 1020, but the results look impressive.
Of course all these shots are from Apple so they may have been perfectly lit, and edited to perfection. Nonetheless they show the levels that the camera can achieve. And with that small lens and 8MP sensor these are impressive enough to replace you digital camera with ease.