At first glance, the Tamron 20-40mm f/2.8 is a bit of an odd duck. It’s not an ultrawide lens, but it’s not really a standard zoom lens either. It’s kind of in between. Next time you go out on a photo walk, should you pick this up instead of a Tamron 28-75mm f/2.8 or 17-28mm f/2.8? Let’s take a look.
- Great colors
- Weather sealed
- No manual focus switch
Tamron 20-40mm f/2.8 — Technical specifications
All technical specifications for the Tamron 20-40mm have been taken from the B&H website:
- Minimum focus distance: 6.7” / 17mm
- Maximum magnification: 0.26x
- Macro reproduction ratio: 1:3.8
- Focus type: Automatic
- Image stabilization: No
- Filter size: 67mm (front)
- Weight: 12.9oz / 365g
Tamron 20-40mm f/2.8 — Ergonomics and build quality
Similar to most Tamron lenses, the 20-40mm f/2.8 has a modest but good build quality. It’s sporting a plastic body with a metal mount and solid weather sealing. The lens is very light but feels premium when in the hand.
The Tamron 20-40mm has a nice size zoom ring with a short throw. The focus ring is positioned at the front of the lens. It feels smooth and spins easily.
One thing noticeably missing from the Tamron 20-40mm is an AF/MF switch. I don’t use that switch often, but there were a few times while using the lens that I wish I had one available.
It should be noted that you can still use manual focus with the lens, you will just have to select it in your camera menu instead of on the body of the lens.
Tamron 20-40mm f/2.8 — In the field
The Tamron 20-40mm f/2.8 surprised me. At first, I wasn’t sure what I should use it for because the 20-40mm range struck me as an odd focal range. My wife and I traveled to Dallas, TX for the holidays so I thought, why not bring the Tamron 20-40mm f/2.8 along and see how it does as a travel companion?
For this purpose, the Tamron 20-40mm absolutely shined. Being so light and compact paired with my Sony A7iv, I could carry this combo with me everywhere with great results. The lens was fun to use and I found myself really enjoying using it.
Tamron 20-40mm f/2.8 — Autofocus performance
During my testing, the Tamron 20-40mm f/2.8 performed well. It is fast and accurate. The motors are quiet and I could see this being a good lens for gimbal work.
I had a few times while using continuous autofocus where the focus wouldn’t pull as I zoomed out. It didn’t happen every time but there were a few instances. I’m sure this could be corrected with settings or possibly a future software update.
Tamron 20-40mm f/2.8 — Image quality
Image quality with the Tamron 20-40mm is great. The images are tack sharp and beautiful.
Distortion control and vignetting
As you might expect with a wider zoom lens, there is some distortion and vignetting. It’s quite controlled at the wide end but can be a little heavier at the long end.
There is a fair amount of pincushioning, but it is very manageable and can easily be corrected during the post-editing process.
Ghosting and flaring
During my time with the Tamron 20-40mm, I didn’t experience much ghosting or flaring. I was shooting mostly during the middle of the day and it performed great.
I found the photos taken with the Tamron 20-40mm f/2.8 to be very sharp. I would have no problem trusting this lens.
Bokeh with the Tamron 20-40mm is nice with a good falloff. The Bokeh balls are beautifully round, even wide-open at f/2.8
I found the color rendition on this lens to be very good. I took the Tamron 20-40mm with me to an art museum while out exploring Dallas and was very happy with the results. The images below have been corrected for vignetting but are otherwise unedited so you can see the results.
Artist — Obey Giant at Dallas Contemporary