TAMRON 100-400mm f/4.5-6.3 DI VC USD

If you feel that bigger is better, this will be the preferable option from Tamron’s two offerings

Athird heavier and larger than Tamron’s 70-300mm lens on test, this lens goes toe-to-toe with Sigma’s 100-400mm. It’s almost identical in terms of zoom and aperture, but the Tamron focuses closer at 1.5m, with a slightly larger 0.28x max magnification ratio. Both lenses have ring-type ultrasonic AF systems and four-stop stabilizers, with switchable panning modes.

Whereas the Sigma has a three-position AF limiter switch for locking out the short or long end of the range, the Tamron has a single ‘Limit’ position on the AF/MF focus mode switch. When engaged, this can limit the AF range on one side of the current focus distance position or the other. As with the Sigma, an optional USB docking station is available, this time in the shape of Tamron’s TAP-IN Console. Again, firmware updates and fine-tuning for AF accuracy can be applied, but the Tamron lacks extra Custom modes available via a physical switch on the lens barrel.

Build quality feels sturdy and robust, and the Tamron features weather-seals and a fluorine coating on its front element. The optical path includes an LD (Low Dispersion) element and nanostructure coatings to minimize ghosting and flare. Unlike with the Sigma, an optional tripod mount ring is available for this lens, which improves balance when using a tripod or monopod.

Performance

Solid performance in all areas ranges from fast AF and effective stabilization to impressive centresharpness throughout the zoom range, even when shooting wideopen. But corner-sharpness drops off a bit at the short end.