While I'm still analyzing the D600 and D7100 low light shots, here are more comparison shots between the D600 and D7100, this time in daylight. For this test, I used the Sigma 35 1.4 on the D7100 and the Tamron 28-75 (at around 52mm) on the D600. I know, your first reaction is that it's not a fair comparison because the Sigma is considered one of the sharpest lenses, whereas the Tamron is sharp in the center but it's not in the same league.