Small Lens, Big Impact: Tamron’s 20-40mm f/2.8 tested

By Anthony McKee | 28 October 2026
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If you looked in the camera bag of any news photographer back in the 1990’s, you probably would have discovered a 20-35mm f2.8 zoom lens.

Canon released an EF-mount version of this lens in 1989 and Nikon released their version in 1993. Both lenses were relatively compact but they covered the main wide-angle focal lengths and the f2.8 maximum aperture made both lenses useful in almost any light condition.

The old Nikon 20-35mm f2.8D next to the new Tamron 20-40mm f2.8 Di III VXD lens.
The old Nikon 20-35mm f2.8D next to the new Tamron 20-40mm f2.8 Di III VXD lens. Notice the aperture ring, aperture lock, Manual/Autofocus selector switch and focus scale on the Nikon; by comparison the Tamron is a very simple in its design.

I bought my Nikon 20-35mm f2.8 AF-D lens in late 1993 and it served me well for over 20 years. When I went to replace this lens though, I discovered there was no replacement. Most lenses were either too wide (the 14-24mm f2.8), too slow (the 16-35mm f4) or just too big.

Even as Nikon’s Z-mount system evolved there was no equivalent - Nikon’s Z 14-30mm f4 lens is great for landscape and architecture, but its not quite long enough for people work - and its f4.

That all changed last week when a Tamron 20-40mm f2.8 Di III VXD lens was dropped at my door. Like quite a few Tamron lenses, the 20-40mm was originally designed for the Sony E-mount but it has recently been adapted for the Nikon Z system.

The first thing you notice when you unpack this lens is its compact size; its just 88.7mm in length, 74.4mm wide and it weighs a mere 385-grams; that’s about the same size and weight as Nikon’s 50mm Z f1.8 S lens.

Over the years I have learnt that 20mm is about as widest focal length that you can use for doco and street photography before distortion becomes too much of a concern. This photo was made in Bourke Street Mall at 20mm. The exposure was f5.6 at 1/160th. ISO-400.
Over the years I have learnt that 20mm is about as widest focal length that you can use for doco and street photography before distortion becomes too much of a concern. This photo was made in Bourke Street Mall at 20mm. The exposure was f5.6 at 1/160th. ISO-400.

Unlike many lenses on the market nowadays, the Tamron 20-40mm f2.8 is also very simple in its design. The zoom ring is located on the waist of the lens and marked with the 20, 24, 28, 35 and 40mm focal length settings, while near the front of the lens is the focus ring. That’s all!

There is no AF/MF switch, no function button or LCD display. There is a USB-C port on the side of the lens for updating firmware, but that’s all. This is a very basic lens.

Image: Anthony McKee
In these two photos you can see the difference between a portrait shot at the 20mm setting, and at the 40mm setting. The 20-40mm focal range is perfect for street and doco photography because it is not so wide you get obvious distortion, and it is not so long that you are loosing that sense of place that wide-angle lenses offer you.
In these two photos you can see the difference between a portrait shot at the 20mm setting, and at the 40mm setting. The 20-40mm focal range is perfect for street and doco photography because it is not so wide you get obvious distortion, and it is not so long that you are loosing that sense of place that wide-angle lenses offer you.

Despite being lightweight, the construction is good, with a metal mount ensuring a sturdy connection to the camera body and rubber gaskets providing moisture sealing.

The lens has an internal focusing mechanism although the front of the lens does move forward 1-centimetre as you zoom from 40mm to 20mm. Notably, there is a 67mm filter thread on the front of the lens, and this does not rotate during focus or zooming.

The Tamron 20-40mm f2.8 Di III VXD is one of the smallest constant f2.8 zoom lenses on the market, which makes it the perfect lens to carry with you all day. This portrait of an “oodle” was made with the lens at the 30mm setting, the exposure was f5.6 at 1/250th, ISO 800.
The Tamron 20-40mm f2.8 Di III VXD is one of the smallest constant f2.8 zoom lenses on the market, which makes it the perfect lens to carry with you all day. This portrait of an “oodle” was made with the lens at the 30mm setting, the exposure was f5.6 at 1/250th, ISO 800.

Optically, the lens contains 12 elements in 11 groups, including aspherical elements, low dispersion glass, anti-reflection coatings and a fluorine coatings to protect the front element from water and oils.

My first test was to check its sharpness of the lens and I was immediately impressed. Even at f2.8 the detail in the image is very good at all focal lengths, even out into the corners.

The Tamron 20-40mm f2.8 Di III VXD lens might not have built in vibration reduction but you don’t really need it nowadays thanks to the 8 stops of image stabilisation that you get on cameras like the Nikon Z6III. This photo of a hat shop in a Melbourne Mall was shot handheld at 1/3rd of second, f10 at ISO 400.
The Tamron 20-40mm f2.8 Di III VXD lens might not have built in vibration reduction but you don’t really need it nowadays thanks to the 8 stops of image stabilisation that you get on cameras like the Nikon Z6III. This photo of a hat shop in a Melbourne Mall was shot handheld at 1/3rd of second, f10 at ISO 400.
Image: Anthony McKee
Just to appreciate how clever this lens can be on a camera like the Nikon Z6III, this photograph of people on an escalator was captured handheld at 1/4 of a second, f13 at 400 ISO. The focal length was 20mm. If you check the cropped image (taken from the upper left of the frame) you will see that the detail is good enough that you can actually read some of the titles on the books.
Just to appreciate how clever this lens can be on a camera like the Nikon Z6III, this photograph of people on an escalator was captured handheld at 1/4 of a second, f13 at 400 ISO. The focal length was 20mm. If you check the cropped image (taken from the upper left of the frame) you will see that the detail is good enough that you can actually read some of the titles on the books.

The sharpness improves modestly as you close down to f4 and f5.6, but as someone who frequently shoots at wide apertures, I would happily use this lens wide open, particularly for my people work. The one thing I did notice is that the focus does shift as you zoom the lens - so, zoom, then focus.

Nikon Z cameras do a great job of managing vignetting and distortion in lenses, and unless you turn off the automatic corrections you won’t notice any problems.

Lens vignetting and distortion are not the problems they used to be thanks to the automatic corrections in most modern cameras. This image was shot at the 20mm setting and it is near impossible to fault the overall exposure and geometry of this wall. The exposure was f4 at 1/125th at 800 ISO.
Lens vignetting and distortion are not the problems they used to be thanks to the automatic corrections in most modern cameras. This image was shot at the 20mm setting and it is near impossible to fault the overall exposure and geometry of this wall. The exposure was f4 at 1/125th at 800 ISO.
The compact size of the Tamron 20-40mm f2.8 lens combined with its silent focusing means this lens is not very intimidating, even to cute animals. This image was shot at the 40mm setting at f5.6, 1/3200 at 400 ISO and thanks to the Nikon’s 3D focusing with pet detection the eyes are whisker sharp.
The compact size of the Tamron 20-40mm f2.8 lens combined with its silent focusing means this lens is not very intimidating, even to cute animals. This image was shot at the 40mm setting at f5.6, 1/3200 at 400 ISO and thanks to the Nikon’s 3D focusing with pet detection the eyes are whisker sharp.

With the corrections TURNED OFF in the camera this lens does exhibit the usual vignetting and distortion you would find in most zoom lenses; there is about 1-stop of vignetting at the 20mm setting and some barrel distortion, while at 40mm there is minor pincushion distortion.

Again, if these corrections are turned on in your camera (and they are by default) and you never notice these common faults.

For me, the real test for the Tamron 20-40mm 2.8 lens was on the street. Aside from Nikon’s Z 24-50mm f4-6.3 lens, the Tamron 20-40mm f2.8 is one of the smallest wide-angle zooms available for any full-frame camera system.

Some landscape photographers are always going prefer premium lenses, but if you are looking to save a some money (and some weight in your backpack) I would definitely be considering the Tamron 20-40mm f2.8 as an option. This image was captured near Lake Fyans in the Grampians using the 20mm setting; the exposure was f11 at 1/100 at ISO 100.
Some landscape photographers are always going prefer premium lenses, but if you are looking to save a some money (and some weight in your backpack) I would definitely be considering the Tamron 20-40mm f2.8 as an option. This image was captured near Lake Fyans in the Grampians using the 20mm setting; the exposure was f11 at 1/100 at ISO 100.
An example of how close the Tamron 20-40mm lens can focus at the 20mm setting. This lichen on a tree trunk in the Grampians was captured at f8, 1/80th of a second, ISO 400.
An example of how close the Tamron 20-40mm lens can focus at the 20mm setting. This lichen on a tree trunk in the Grampians was captured at f8, 1/80th of a second, ISO 400.

This makes the lens both discreet and inoffensive; with larger wide-angle zooms on your camera you look like a pro, but the Tamron 20-40mm makes you look more like a tourist or an amateur. In other words, harmless.

During a wander through Melbourne’s CBD I was able to walk up to people and get interesting photos without any hassles.

Focusing with this lens is exceptionally fast and silent thanks to Tamron’s VXD (Voice-coil eXtreme-torque Drive) focus mechanism. And while there is no vibration reduction mechanism in this lens, the image stabilisation in my Nikon Z6III was more than capable of letting me handhold this lens at shutter speeds as low as 1/2 of a second with great results.

While 20mm is often wide enough for most landscape photography, the 40mm setting is usually as narrow as I need to go. This image of a billabong in the Grampians was shot at 40mm with the exposure being f6.3 at 1/20th, ISO 200.
While 20mm is often wide enough for most landscape photography, the 40mm setting is usually as narrow as I need to go. This image of a billabong in the Grampians was shot at 40mm with the exposure being f6.3 at 1/20th, ISO 200.
Another example of how close the Tamron 20-40mm f2.8 lens can focus. This flower was photographed with the 20mm setting; the exposure was f2.8 at 1/1250th, 400 ISO.
Another example of how close the Tamron 20-40mm f2.8 lens can focus. This flower was photographed with the 20mm setting; the exposure was f2.8 at 1/1250th, 400 ISO.

On the weekend I went bush with the camera and again, the lens’s compact size and minimal weight meant it was a joy to use. One feature I love about this lens, is its close focusing ability; at the 40mm focal length you can focus down to 29cm and at the 20mm focal length you can focus down to 17cm.

This lens won’t replace a good macro lens but it will help you get closer to nature. Being spring I did get caught in some rain but the moisture proofing combined with the fluorine coating on the lens meant I could keep shooting without too much fuss.

But why am I so obsessed by this focal range? Over the years I’ve learnt that 20mm is as wide as I need to go without getting too much distortion in my images, and 35mm is as long as I want to go with losing the engagement a wide-angle lens gives you with a subject and the environment.

Yes, there are lenses available with broader zoom ranges, but I don’t want to get home and discover I zoomed too wide for a shot, or an environmental portrait looks more like an exercise in bokeh because I zoomed out too far. Just as many photographers like to work exclusively with one prime lens, I discovered decades ago that the 20-35mm range is where I like to dance.

Overall I am very impressed with this lens, and it has officially replaced my old Nikon 20-35mm f2.8 lens. It is noticeably sharper than the old lens, particularly in the corners, but it is also more compact and rugged.

With this lens and a 70-200mm f2.8 I could easily photograph a wedding, and partnering this lens with an 85mm f1.8 I would have the perfect travel kit. What I do know is that this lens will be great for my doco work. I’m happy again.

Handling ★ ★ ★ ★ ★

This is one of the most compact, fast (f2.8) wide-angle zooms on the market, and its simple design makes it exceptionally easy to work with. Snap fast focussing also means you should never miss a moment.

Features ★ ★ ★ ★

A very practical zoom range combined with a excellent focusing range means this lens is perfect for most wide-angle needs. The moisture proofing and fluorine lens coating will make this usable in most conditions.

Image Quality ★ ★ ★ ★ (4.5)

The image quality from this lens is very good, particularly for an f2.8 lens at this price point. Sharpness is very good corner to corner and colour rendering and contrast are also good.

Value for money ★ ★ ★ ★ ★

My original Nikon 20-35mm f2.8D cost over $3000 - in 1993. The Tamron 20-40mm f2.8 Di III VXD is optically superior and great buying at just $1,099 in today’s money!

gold award

Final Word

Some people obsess over large lenses with big zoom ranges, but quite often its the smaller lenses that can be more useful to you. I think the Tamron 20-40mm f2.8 Di III VXD is one of those gems.

SPECS

Model - Tamron 20-40mm f2.8 Di III VXD lens
Lens Mount - Nikon Z
Format Coverage - Full Frame (FX / 24mm x 36mm).
Focal Length - 20-40mm
Maximum Aperture - f2.8
Minimum Aperture - f22
Optical Design - 12 Elements in 11 Groups.
Aperture Blades - 9
Minimum Focus Distance - 17cm at 20mm; 29cm at 40mm.
Magnification - 1:3.8 Macro Reproduction Ratio, 0.26x Magnification
Focus Type - Autofocus with manual override
Image Stabilisation - No, relies on In-Camera Image Stabilisation
Filter Size - 67mm
Dimensions (D x L) - 77.4mm x 88.7 mm
Weight - 385 grams
Supplied with - Front and rear caps plus a lens hood

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