All the lens reviews on this site also include 100% crops from ISO charts, showing the center, middle, and corner of the frame.


The 24-70 ISO chart, is shot only with the 1DsIII, but as that'salso a full frame camera with a similar number of megapixels, it should make for a decent comparison. Using this tool you can check the expected sharpness and contrast at each focal length and f value.


edit: You can also check camera and lens combos at pixel-peeper.com, the link I've included is limiting it to 5DmkII, 24-70L, f/2.8 only. There are 108 images matching that.