Tamron 20mm f/2.8 Di III OSD M1:2 Review
The 20mm f/2.8 Di III OSD M1:2 ($349) is another affordable, well made Tamron lens available exclusively for Sony's full-frame mirrorless camera system. It's much better than you'd expect for the price, and complete with weather protection. There are some drawbacks, including an autofocus system that's not as quiet as we'd expect, but it's a very good prime lens, especially when you take its very wide angle of view and low price into account.
Short and Squat
The 20mm f/2.8 is a short, squat prime lens. It measures 2.5 by 2.9 inches (HD), weighs 7.8 ounces, and supports 67mm front filters. Tamron includes a reversible, petal-style lens hood, as well as front and rear caps. It's only sold for Sony mirrorless cameras, and is compatible with both APS-C and full-frame sensor models.
The barrel is made from polycarbonate. It's a sturdy composite, not the cheaper-feeling plastic used by Rokinon in its competing 18mm F2.8 AF ($399), also available for Sony systems. It also includes du...
The Tamron 20mm f/2.8 Di III OSD M1:2 lens is well made, affordable, and plenty sharp, but it doesn't offer lightning-fast autofocus.
Light and compact; Inexpensive; Excellent resolution; 1:2 magnification; Dust, splash, and fluorine protection
Uncorrected images show barrel distortion and vignette; Audible autofocus operation; Exhibits breathing during focus adjustment