Initial tests with the first Tamron lens received showed that it had a substantial autofocus dysfunction similar to that reported for many lens samples in reviews on Fred The lens would not autofocus accurately, but functioned acceptably when manually focused. The dealer sent a replacement lens on request. See data below. Data on the main review page is from tests with the second sample of the Tamron SP AF 17-50mm f/2.8 XR LD lens. Because others have rated this lens highly and because of variation in performance of the first two lenses, I obtained a third new sample of the lens from another dealer. Samples 1 and 2 were USA warranty models. Sample 3 was an international warranty model. All were made in Japan.

Test shows signficant Tamron autofocus error with the first lens sample on a Canon EOS-20D camera and lenses tested at 50mm.

The second lens sample received from the dealer as a replacement functioned normally and was used in all subsequent tests.
{short description of image} 50% MTF Performance at 50mm did not differ significantly between Sample 1 lens manually focused and Sample 2 lens with normal autofocus. Sample 3 lens does not have appreciably different function.
Resolution performance does not significantly between lens sample 2 and lens sample 3.

Review Main Page