Lenses

Review: Tamron 20mm F2.8 Di III OSD (One of the Best Wides for Sony)

Chris Gampat
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02/24/2020
6 Mins read
Chris Gampat The Phoblographer Tamron 20mm F2.8 DI III OSD product images 2.81-160s3200 2

Last Updated on 03/05/2020 by Mark Beckenbach

With the Tamron 20mm f2.8 Di III OSD, a photographer is getting a lot for their money, including distortion.

The Tamron 20mm f2.8 Di III OSD is part of the trio that the company announced last year. It’s lightweight, weather-sealed, and priced at only $349. This lens is pretty much an impulse buy. You’re not only getting Tamron’s level of fantastic build quality, but also great images that you’re going to love. Of course, this isn’t a lens for everyone: not every photographer needs a 20mm lens. But if you shoot landscapes or buildings, then then the Tamron 20mm f2.8 Di III OSD is a lens that can keep your overall travel pack very light. It’s got some issues with distortion, but that can be fixed.

Pros and Cons

Pros

  • Well built
  • Affordable
  • Nice colors
  • Tamron is embracing Mirrorless with a small and lightweight offering.
  • Weather sealed very well; it survived a few hours in the rain.
  • Autofocuses quickly
  • Priced at only $349

Cons

  • This is one of the most heavily distorted lenses we’ve tested in a while. You can use that to your advantage, or you can correct it in post.

Gear Used

We tested the Tamron 20mm f2.8 Di III OSD with the Sony a7r III.

Tech Specs

Taken from Tamron’s website

Model F050
Focal Length 20mm
Maximum Aperture F/2.8
Angle of View
(diagonal)		 94°30′(for full-frame mirrorless format)
Optical Construction 10 elements in 9 groups
Minimum Object Distance 0.11m (4.3 in)
Maximum Magnification Ratio 1:2
Filter Size Φ67mm
Maximum Diameter Φ73mm
Length* 64mm (2.5 in)
Weight 220g (7.8 oz)
Aperture Blades 7 (circular diaphragm)**
Minumum Aperture F/22
Standard Accessory Flower-shaped hood, Lens caps
Compatible Mounts Sony E-mount

Ergonomics

The Tamron 20mm f2.8 Di III OSD is a very small lens. It’s not a pancake offering though. Instead, liken this to more of a Mandarin or a Clementine. Oh, and it’s weather-resistant.

When you get close to the Tamron 20mm f2.8 Di III OSD, you’ll notice the single control. It’s the focusing ring. There is also a detachable lens hood that comes with it.

Did we mention that the Tamron 20mm f2.8 Di III OSD is weather sealed? Oh okay, good. Because part of that sealing comes from the fact that no switches are on the side of the lens.

The Tamron 20mm f2.8 Di III OSD is honestly small and light enough that a photographer can use it on an a7, a9, or a6000 series body with no issues. It’s such a great size.

If you want to shoot with this lens and a filter, look for size 67mm. And then go have fun!

Build Quality

The Tamron 20mm f2.8 Di III OSD was tested for a few hours in the cold and rain of late January, 2020. Specifically, we took it into the rain during the opening ceremonies of NY’s Chinese New Year. It also traveled with us to a very foggy salt marsh. This lens shrugged off all that mother nature threw at it. For $350 you’re getting a fantastic value when it comes to build quality. The body’s size is almost like a piece of handheld fruit that you’d enjoy for a snack. If you want an affordable, well built wide-angle prime, then the Tamron 20mm f2.8 Di III OSD will be the apple of your eye. I particularly believe landscape photographers will really adore this lens for the small size, light weight, etc. Combine it with Sony’s high megapixel cameras and a tripod for the best results.

Ease of Use

Novice photographers and the more experienced alike won’t have an issue with the Tamron 20mm f2.8 Di III OSD. There are no controls whatsoever on the body, and everything is done through the camera. That’s what you get at this price point. Personally, I’d prefer a focusing ring that snaps back and allows me to manually focus. Arguably though, you don’t need it with the Sony system. All you do is mount the lens to the camera, point, focus, and shoot. You won’t have any trouble.

Autofocus

We took the Tamron 20mm f2.8 Di III OSD into both good and bad lighting. It performed well in both situations with only a few moments where it couldn’t nail focus. These situations involved continuous autofocus and shooting wide open. Despite this being a wide-angle prime, it sometimes had trouble when focusing closely on a plant moving about in the wind. To be fair, lots of cameras and lenses have this issue. It just means you need to be careful. The focusing otherwise is good enough for street photography in good lighting. When the lights go down, it becomes more difficult. This is a situation where I doubt it will be practically used, but folks like to experiment. For landscapes and architecture, the Tamron 20mm f2.8 Di III OSD will do just fine.

On Reports of Autofocus Issues

Lots of folks I spoke to about this lens talked about autofocus issues. I encountered that situation once. But then I remember just how awful Sony’s mount is for protection against debris. I cleaned the contacts of both the lens and the camera with Isopropyl alcohol and I didn’t have delays after that. Here’s how you do that. Basically, just maintain your camera and you’ll be fine.

Image Quality

Editor’s Note: Some of these images have been edited, but most haven’t.

The Tamron 20mm f2.8 Di III OSD shines in pretty much every single way, except for distortion. To get the bad out of the way first, it is quite distorted, but you can easily fix that in Capture One. Alternatively, you can embrace the look of it in the right situations. Otherwise, this lens has nice bokeh as a result of its close focusing abilities. It also has beautiful colors and great sharpness. I can’t really complain about a lens that’s this affordable.

Bokeh

This is a wide-angle lens with an f2.8 aperture. One would think that the bokeh here would be negligible, but in the right situations it’s almost creamy. Of course, I don’t recommend using this lens for just the bokeh features. There’s a lot more to like about it.

Chromatic Aberration

Yes, there’s distortion: we’ve established that. But otherwise, this lens doesn’t have any sort of fringing issues or other major problems worth complaining about. When you’re doing it at this price point, there’s a lot of recognition that must be given.

Color Rendition

The colors from the Tamron 20mm f2.8 Di III OSD are pretty saturated. However, I’ve seen Rokinon, Sony, and Sigma lenses that are more so. We tend to use the Deep or Clear color profiles on the Sony a7r III. As many Sony photographers should know, these get embedded into the RAW file. We could get even more vivid, but these are good enough for most photographers. Anything else that you want can be fixed in post or enhanced with a Polarizing filter.

Sharpness

The Tamron 20mm f2.8 Di III OSD is a pretty sharp lens. Are there sharper on the market? Totally. Are there sharper lenses at this size and price point on the market? No. I really like Sony’s own 24mm f1.4 G Master and the Zeiss 25mm f2 Batis, but those are much more expensive. Besides, Tamron has its own 24mm lens to compete with those anyway.

Extra Image Samples

Conclusions

Likes

  • Small
  • Light
  • Weather sealed
  • Fast to focus in most situations
  • It’s $349

Dislikes

  • Though the distortion can be fixed in post, I’d rather not do it.

The Tamron 20mm f2.8 Di III OSD is a great lens for what it is. Our only major problem is the distortion, but that’s easily fixed in post-production. This lens has great image quality with nice bokeh (when possible), very good sharpness, and beautiful colors. On top of all that, it’s lightweight and built like a tank. Best of all, the price and portability are things you’ll be very happy with.

We’re awarding the Tamron 20mm f2.8 Di III OSD four out of five stars. Want one? It’s $349.

autofocus Bokeh build quality color rendition ergonomics image quality sharpness sony tamron Tamron 20mm f2.8 Tamron 20mm f2.8 Di III OSD
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Chris Gampat is the Editor in Chief, Founder, and Publisher of the Phoblographer. He provides oversight to all of the daily tasks, including editorial, administrative, and advertising work. Chris's editorial work includes not only editing and scheduling articles but also writing them himself. He's the author of various product guides, educational pieces, product reviews, and interviews with photographers. He's fascinated by how photographers create, considering the fact that he's legally blind./ HIGHLIGHTS: Chris used to work in Men's lifestyle and tech. He's a veteran technology writer, editor, and reviewer with more than 15 years experience. He's also a Photographer that has had his share of bylines and viral projects like "Secret Order of the Slice." PAST BYLINES: Gear Patrol, PC Mag, Geek.com, Digital Photo Pro, Resource Magazine, Yahoo! News, Yahoo! Finance, IGN, PDN, and others. EXPERIENCE: Chris Gampat began working in tech and art journalism both in 2008. He started at PCMag, Magnum Photos, and Geek.com. He founded the Phoblographer in 2009 after working at places like PDN and Photography Bay. He left his day job as the Social Media Content Developer at B&H Photo in the early 2010s. Since then, he's evolved as a publisher using AI ethically, coming up with ethical ways to bring in affiliate income, and preaching the word of diversity in the photo industry. His background and work has spread to non-profits like American Photographic Arts where he's done work to get photographers various benefits. His skills are in SEO, app development, content planning, ethics management, photography, Wordpress, and other things. EDUCATION: Chris graduated Magna Cum Laude from Adelphi University with a degree in Communications in Journalism in 2009. Since then, he's learned and adapted to various things in the fields of social media, SEO, app development, e-commerce development, HTML, etc. FAVORITE SUBJECT TO PHOTOGRAPH: Chris enjoys creating conceptual work that makes people stare at his photos. But he doesn't get to do much of this because of the high demand of photography content. / BEST PHOTOGRAPHY TIP: Don't do it in post-production when you can do it in-camera.