Hi, and welcome to the TDP forums!


I'm not sure how Bryan processes the vignetting test images (he states he shoots the ISO 12233 shots in RAW, but I don't see a similar statement for the vignetting tests). That might be relevant, based on this statement from the Nikon vignetting results on photozone.de:


Quote Originally Posted by photozone.de
We're performing our vignetting analysis based on (uncorrected) JPEGs straight from the camera. The Nikon D3x has a rather moderate contrast (gradation) characteristic, resulting in comparatively low vignetting figures - the corresponding Canon figures are roughly 40% higher due to the more aggressive default contrast setting.

Even if Bryan uses RAW, there may be different defaults in DPP vs. ViewNX (although with a neutral picture style that shouldn't matter).


Although PZ hasn't tested many Nikon lenses, the 50mm f/1.4 has ~2 EV of vignetting wide open (but they didn't test the Canon 50mm f/1.4). On the one pair of lenses with equivalent focal length and max aperture, the 24-70mm f/2.8 zooms, at 24mm f/2.8 the Canon has ~2 EV of vignetting, and the Nikon has ~1.5 EV - the Canon lens is almost exactly the 40% higher they mention in their 'disclaimer', meaning based on the PZ data there's no significant difference in vignetting between those lenses (at those exposure settings).


However, Bryan's vignetting shots for those same two lenses show the Nikon 24-70mm f/2.8 @ 24mm f/2.8 barely reaches 1 EV, whereas the Canon24-70mm f/2.8 @ 24mm f/2.8 goes over 3 EV. So, there's clearly a difference between Bryan's results and the PZ data (and in a way that doesn't look good for the Canon lenses...).


Hopefully Bryan will run across this and chime in...