When mounted on a Canon EOS 5D Mark II, the Tamron SP 24-70mm F2.8 Di VC USD achieves an overall DxOMark Score of 24, the second highest score in our database for a high-speed (f2.8) standard zoom. Although the Tamron has well-controlled chromatic aberration, it’s the excellent transmission values and high sharpness, measured at an average of 15P-Mpix, that really make this lens stand out.
On the downside, there’s some noticeable vignetting in the corners at the maximum aperture at 24mm and 70mm. It is slightly lower in the mid-focal lengths but it never really goes away completely when stopped down. It just gets less noticeable.
Another shortcoming is distortion. Zoom lenses like this tend to exhibit barrel distortion at the wide end altering to pincushion at the other. While our figures are lower than average at 0.3% for this type of zoom, the Tamron has, in fact, quite heavy barrel distortion at 24mm.