After familiarizing themselves with the topic, bidders put their money on the Tamron 28-75 / 2.8 and the Sigma 24-70 / 2.8. Nikon achieves near-perfect success with nearly every shot, but Tamron and, especially, Sigma sit on the bench nervously puffing on cigarettes because their focusing frequently misses the mark—sometimes by as much as 50%. Nikon also has superior focus in low light compared to the larger-holed glasses mentioned above.