First Looks at Tamron 100-400mm f/4.5-6.3 Di VC USD Lens Image Quality

Image quality test results have been added to the Tamron 100-400mm f/4.5-6.3 Di VC USD Lens page.

It was interesting to see Tamron announce a 100-400mm lens not terribly long after the Sigma 100-400mm f/5-6.3 DG OS HSM Contemporary Lens introduction. The Sigma was a big hit, delivering great image quality in a small, lightweight package that was nicely built and well-featured for an especially-popularity-driving low price. With these two lenses being very similar, including the same street price, I am anxious to learn which is the best. The image quality results are a good start in that determination.

Of importance is a short discussion of the corner performance equivalency of this lens copy at the wider half of the focal length range. As long as the lens elements are properly constructed/dimensioned, a properly-aligned lens will deliver equal image quality in each corner. The Tamron 100-400 we are testing modestly favors the left corners. That of course places it at a disadvantage in the site's image quality tool as the right corner shows there.

For clarification, here is the top-left vs top-right corner comparison:

Because the Sigma 100-400 is this lens' closest competitor, I added that lens' wide open 100mm sample to the bottom. While the Sigma crop appears slightly sharper than the Tamron crop, I doubt that most will find that difference to be of significance in the overall comparison.

Most of our review lenses are off-the-shelf retail and your chances of getting a slightly misaligned one are as good as ours. This defect can happen, but ... no one is happy when they learn that their lens has an issue (and it costs us a lot of time to minimally explain what is happening and ideally to re-test another lens). We'll try to find time to test another lens copy at some point, but for now, try to visualize the above differences when viewing the following comparisons.

Tamron 100-400mm Lens compared to Sigma
Tamron 100-400mm Lens compared to Canon
Tamron 100-400mm Lens compared to Sony (different resolution cameras used)

The Tamron 100-400mm f/4.5-6.3 Di VC USD Lens is in stock at B&H | Amazon | Adorama.

We'd love to hear your thoughts on the new Tamron 100-400mm VC Lens. Leave them in the comments section!