If you’ve seen my video comparing the Canon and the original Tamron 24-70 f/2.8 VC USD, you know that they were already very closely matched lenses. With the improvements made in the Tamron G2, how do they compare now?
You can see all of the details in the video above, but I’ll summarize it quickly like this: when it comes to image quality, the Canon remains slightly sharper away from the center of the frame at the wide end of the zoom range, though the difference is usually modest. By f/5.6, the differences are almost gone, and at f/8, I’d be hard pressed to pick one over the other. At the 70mm end, however, the Tamron is often sharper away from the center and near the borders, and the differences in the center are negligible. Again, the image quality converges by f/5.6 or so.
The Tamron’s image stabilization remains excellent, and provides usable images down to 1/15th of a second and sometimes slower.
While the Canon still has the most reliable autofocus performance (when shooting with my Canon 5D Mark III), the Tamron was also excellent in all but a single shooting situation: shooting bursts of an approaching subject that suddenly changes speed or direction.
Ultimately, I’d recommend the Tamron 24-70 G2 lens for most photographers who would like to save $500 and leverage the power of image stabilization. My only reservation would be for those photographers who primarily shoot sports. Those photographers should check the AF performance on their camera models, first.