The Tamron 11-20mm F2.8 Di III-A RXD ($829) is the first direct competitor to Sony’s long-running 10-18mm F4 OSS. Tamron’s lens is better built, with the weather protection Sony’s wide zoom lacks, and brighter F2.8 optics. It’s the lens to get for your a6000-series camera if you’re looking for a broader view, though vloggers may still prefer the Sony 10-18mm for its stabilized optics.
Made for Outdoor Photographers
The Tamron 11-20mm is available exclusively for Sony mirrorless cameras. Its optics are made to cover the APS-C image sensors used by models in the a6000 series and the recent ZV-E10 vlogging camera.
It maintains an F2.8 maximum aperture across its focal range, netting twice as much incoming light as the Sony E 10-18mm F4 OSS. The Tamron lens is bigger all around because of it, about 3.4 by 2.9 inches (HD) and 11.8 ounces, to the Sony’s 2.5 by 2.8 inches and 9.4 ounces. You can see the two side by side in the photo above.
The Tamron is housed in a polycarbonate barrel, as opposed to the Sony’s aluminum shell, and feels sturdier because of it. It’s also better protected. Tamron includes dust and splash protection here, along with anti-smudge fluorine on the front glass.
The 11-20mm supports the 67mm filter size, and there’s a lens hood included for some extra protection from stray fingerprints and lens flare. Front and rear lens caps are included, but Tamron doesn’t bundle a soft case or pouch—you’re on your own there.
On-lens controls are as basic as it gets, discrete rings to adjust zoom and focus. The zoom control sits mid-barrel and is finished in rubber, with raised ridges so you can find it by feel. The focus ring sits a little further forward and has molded plastic ridges. There’s no focus toggle switch, so you’ll need to dive into the camera menu to change focus modes.
Autofocus is quick and quiet, a good fit for video and stills alike. I used it in continuous focus with the ZV-E10 for vlog footage and found it to be a good fit. There’s a little focus breathing visible when racking from close focus to infinity, but it’s not distracting for shots where the subjects is only moving slightly away or toward camera.
The focus ring turns easily, but with enough resistance to make subtle changes to focus when working manually. The focus response is ramped, so a quicker turn of the ring makes for a more dramatic shift, while slow, deliberate movement is used to make fine adjustments. It’s helpful for still imaging, but videographers tend to prefer a linear response for manual focus.
Wide lenses don’t net macro results given their big angle of view, but most designs support very close focus. The lens locks as close as 5.9 inches, so you can get really close to a subject and capture a big swath of background behind it. When zoomed in, the lens nets 1:4 life-size reproduction at its closest focus point.
Optical stabilization isn’t included, a feature Sony puts in its E 10-18mm F4 zoom. It’s an important consideration as Sony only has a pair of APS-C cameras with stabilized image sensors, the a6500 and a6600. These models include five-axis IBIS, as well as dust and splash protection, making the Tamron an ideal match. If your Sony doesn’t have stabilization, you may prefer the 10-18mm for handheld video and longer exposures without a tripod.
The lens is made for APS-C sensor cameras, but mounts on full-frame models too. I used it with the Sony a7R IV in the field and for lab tests. The a7R IV’s 60MP crops down to 26MP in APS-C, just about matching the resolution of the a6100, a6400, a6600, and ZV-E10. You have the option of using the lens in full-frame mode too, but the optics don’t cover a full-frame sensor, as you can see in the uncropped, full-frame photo from the a7R IV above.
In the Lab
For lab tests, we set the a7R IV to its 26MP APS-C capture mode to photograph our resolution chart and reached to Imatest software for analysis. The pair delivers strong results. At 11mm f/2.8 the central resolution is outstanding, and while we see some drop in clarity toward the edges of an image, they still show strong detail.
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There is some field curvature at play here—our up-close resolution testing shows very low numbers at the edges of the frame because our test chart is flat, but they don’t reflect real-world results. You’ll still want to set the lens to f/5.6 or f/8 for the crispest landscape images.
Resolution remains strong zoomed in. Center resolution is outstanding at 15mm f/2.8 and remains very good toward the edges. We see the sharpest results from edge to edge at f/8, as good as you can expect from a 26MP sensor. The story is the same at the 20mm setting—the lens leaves you wanting nothing in terms of resolution.
Tamron uses rounded blades for the aperture, a choice that draws pleasingly defocused backgrounds when working close, but not the best sunstars. The effect is obtainable—multi-point starbursts are visible around the sun and other bright highlights starting at f/11, but aren’t as clearly defined as through lenses with simpler apertures like the manual-focus, full-frame Venus Laowa 10-18mm, or exotically priced alternatives like the Sony FE 12-24mm F2.8 GM.
Adobe Lightroom already has a correction profile for the 11-20mm, so if you use it to process your Raw images you won’t have to fret about any barrel or pincushion distortion, or a vignette. You do see it in uncorrected photos—there’s some barrel distortion at 11mm and pincushion at 20mm, as well as darkened corners at f/2.8. Digital corrections make them invisible for the most part; if you use your camera in JPG mode they’re applied by default.
An All-Weather Wide Zoom
The Tamron 11-20mm F2.8 Di III-A RXD fills a notable gap in Sony’s APS-C lens catalog—a wide, made-for-APS zoom with dust and splash protection. It has the F2.8 optics you don’t get with Sony’s E 10-18mm F4 OSS, along with a sturdier, weather-protected build. It’s an important feature for outdoor photographers, especially those using the a6500 and a6600, Sony’s two dust-and-splash-protected APS-C cameras.
It omits optical stabilization. That’s less of a concern for a6500 and a6600 owners, as both models include stabilized sensors. But for handheld video and longer exposures without a tripod, a6400 and a6100 photographers, and ZV-E10 vloggers, there’s some reason to spend more on the Sony 10-18mm.
Those use cases aside, we like the Tamron 11-20mm F2.8 Di III-A RXD more. Its optics are stellar, it costs a bit less than Sony’s 10-18mm, and it gathers twice as much light, a plus for night sky use, while only sacrificing a smidgen of wide-angle coverage. Ultimately, it’s an excellent wide-angle addition to your APS-C Sony camera system.
