DxOMark review for the Nikon 24-120, the new constant f/4 aperture on DxOMark.Tuesday November 23 2010 Lens Review
Much more light
As expected, all these improvements help the lens collect much more light. The T-stop results are far better for this new version. From 24 to 85mm, the results are good (f/4.3); from 85 to 120mm, the T-stop climbs to f/4.3 to f/4.6 on a D3x. This is far better than for the old zoom on the same camera, which was in any event limited by its smaller aperture at longer focal lengths.