Now here's a slugfest. Both companies have been consistent innovators in mobile imaging. Despite its fake demo, Nokia signals its Lumia 920 as a flagship imaging device with the Pureview moniker. The camera has an 8.7MP sensor featuring a f/2.0 aperture and backside illumination. The key is its optical stabilization technology, which it calls a "floating point lens." The Lumia 920 has absolutely incredible low-light performance because of these technologies. Barring Nokia's 41MP Pureview 808, this is the best smartphone camera available today.
The iPhone 5 is no slouch either though. The 8MP sensor features an f/2.4 aperture and also has a backside illuminated sensor. Most reviewers rate the two cameras as comparable but give the Lumia a large advantage because of its low-light performance. Perhaps that isn't much of a surprise given Nokia's clear focus on solving that problem.