DxOMark review for the Nikon 24-120, the new constant f/4 aperture on DxOMark.Tuesday November 23 2010 Lens Review
Vignetting at wide apertures
With respect to vignetting, when used on a full frame sensor, the new zoom suffers from a deeper loss of luminosity than its predecessor. The general vignetting score displays minus 1.9 EV for the new 24-120mm versus minus 1.4 for the old version.
If we look at this phenomenon in detail, we notice a pronounced loss of 2 EV at any focal length between f/4 and f/5.6, except at 24 and 28mm, where the loss is present until f/8, and at 85mm where it peaks again at approximately f/6.3.
This all said, between 35mm and 75mm, the lens is almost perfect at wide apertures (between f/4.5 and f/5.6).
When used with an APS-C sensor, however, the new 24-120 mm shows almost no signs of vignetting throughout the zoom range at any aperture.