According to Brain Klug of AnandTech, the Nexus 5 uses the Sony IMX179 CMOS, with a 1/3,2-inch sensor size. The individual pixels are 1.4um in size, which along with OIS should help greatly in low-light situations. So, how good is the Nexus 5’s camera? While reviews of the device are not yet out, some camera samples are already available, thanks to Anirudh Dewani of Google.
I am no pro-photographer so I cannot comment on the images above. The low-light images do, however, look pretty impressive to my naked eye. You can find more camera samples of the Nexus 5 here.