I shot my Tamron 28–75 f/2.8 against a friend’s Nikkor 24-70 on my D700 at a range of apertures and focal lengths. Click on the links below to view full-size images. The short answer is that the Nikkor trounces the Tamron at f/2.8 and f/4.0, but they’re surprisingly close below that. The Tamron also exhibits some decentering: the left side of the frame seems somewhat worse than the right. Also notice the haliation with the Tamron at 70 f/2.8. Still, not bad given the disparity in price!
The Nikkor is a significantly heavier, larger, and more solidly constructed lens with faster autofocus. It also uses the same 77 mm filter diameter as other Nikkor pro glass and has instant manual-focus override. The Tamron is surprisingly lightweight and mostly constructed from plastic. It uses a 67 mm filter diameter, which matches the Nikkor 70–300 f/4.5–5.6. Unfortunately, the threads are plastic, which makes it easy to mis-thread filters. The mount, fortunately, is metal. The Tamron has a built-in motor that takes its time focusing.
The links below will open the full-sized image shot at that particular aperture/focal length combination. They were shot raw and converted using Aperture’s default settings.
Last edit: 10 October 2010