Here's a quick VERY low light photo comparison between the iPhone 4S and iPhone 5S cameras. Shot at night with all of the lights in the room turned off. The only illumination was the light from my 23" Cinema Display. The FM keychain was sitting about 14-inches in front of the display. For both cameras, no flash, handheld, and I touched on the same area of the image to lock focus and exposure for each.
First, the iPhone 4S:
And the iPhone 5S:
I'm impressed! Neither photo is super sharp but, again, it was handheld in REALLY low light. (Gotta hold extra still for shots like that.)
The amount of extra light and significantly lower noise in the 5S image is fantastic! The camera is absolutely my favorite new feature in the 5S!
Mark
First, the iPhone 4S:

And the iPhone 5S:

I'm impressed! Neither photo is super sharp but, again, it was handheld in REALLY low light. (Gotta hold extra still for shots like that.)
The amount of extra light and significantly lower noise in the 5S image is fantastic! The camera is absolutely my favorite new feature in the 5S!
Mark