Tamron 17-28mm F/2.8 Di III RXD review: A surprise unlike any other?

This review starts with the Tamron 28-75mm F/2.8 Di III RXD from last year: thanks to its excellent portability, large aperture of F2.8 and good image quality, the author has watched this lens rise from around 5,000 yuan. Now that it has been on sale for a year, the price on JD.com is still 6,380 yuan (as of 2019/8/15). The Tamron 17-28mm F/2.8 Di III RXD we introduce today belongs to the same series as the Tamron 28-75mm F/2.8 Di III RXD above. Judging from the parameters alone, this lens is smaller (99mm in length) and lighter (420g), adopts an internal zoom design, and its close-up specifications are also at a good level among similar ultra-wide-angle lenses (0.19m). Can the Tamron 17-28mm F/2.8 Di III RXD continue the strong performance of the series? What are the surprises in the experience that are different from the past? This is what this review will answer.

Appearance review

In terms of appearance, the Tamron 17-28mm F/2.8 Di III RXD continues the design language of the 28-75mm F/2.8 Di III RXD, with a 67mm diameter and the "Golden Shining" decorative ring at the waist of the tail unchanged, and the overall length has become shorter. This makes the lens very portable when stored and has a sense of balance when hung on the chest with a strap.

Tamron's 17-28mm F/2.8 Di III RXD has an internal zoom design, so the lens barrel will not extend or shorten when zooming, which can effectively prevent dust from entering the lens and facilitate shooting in bad weather.

The wider ring on the front of the lens is the zoom ring, and the narrower ring on the back is the focus ring. The two have a distinct difference in feel, making it convenient for blind operation.

The Tamron 17-28mm F/2.8 Di III RXD lens has a very clean design. There are no switches on the entire lens. When switching to manual autofocus, you need to set it on the body. In addition, the lens also supports full-time manual function.

The Tamron 17-28mm F/2.8 Di III RXD lens comes standard with a lens hood that supports reverse buttoning and has an internal threaded design.

The front lens is the same as the 28-75mm F/2.8 Di III RXD, with a 67mm lens, which has good filter compatibility. In addition, the front lens uses a fluorine compound coating with waterproof and oil-proof properties, which can effectively prevent dust, water droplets and fingerprints, making it easy to maintain.

The tail end of the lens is equipped with a drip-proof and dust-proof rubber sealing ring, and a full metal mount is naturally also standard.

The lens is perfectly matched with the Sony Alpha 7R IV body, and the overall feel of holding and balance during actual shooting is perfect.

From the design point of view, I agree with Tamron's design concept. With the rapid development of full-frame mirrorless cameras, it is time for the lens market to be segmented. It is a wise choice to launch a small, simple and fully functional lens at this time. After all, a small lens can not only take pictures, but also be used for daily play.

Optical quality test

Although the Tamron 17-28mm F/2.8 Di III RXD is small, its configuration is not ambiguous at all: LD low dispersion lens, XLD extra-low dispersion lens, various aspherical lenses and BBAR anti-glare coating are all equipped. We still need to take a look at its actual performance through actual shooting tests.

Sharpness performance test

We used the method of real shooting + 100% magnified slices for testing as usual. The camera used was the 42.4-megapixel Sony Alpha 7R IV, and we used a tripod + 10-second time-lapse to shoot, with the highest JPEG quality output, and 100% magnified slices of the center and edge of the photo indicated by the red frame were captured as follows:

First, the 17mm end:

Then the 28mm end:

From the results, the Tamron 17-28mm F/2.8 Di III RXD lens performs well. The 17mm end is usable at full aperture in the center, and a slightly smaller aperture can provide better resolution. The 28mm full aperture performance is slightly inferior to the 17mm end, but a slightly smaller aperture to F4 can provide good sharpness. The best aperture of the lens should be F5.6, not F8 as we usually think.

F8 1/80 ISO100

Tamron 17-28mm F/2.8 Di III RXD+SONY Alpha 7R Mark III

100% magnified slice at the center of the above image

100% magnified slice at the edge of the above image

Of course, judging from the actual effect of shooting buildings, the image quality of this Tamron 17-28mm F/2.8 Di III RXD can fully meet the requirements of 40-megapixel resolution: whether in the center or the corners, the resolution performance is satisfactory.

As a small-aperture compact lens, the edge quality of this lens is obviously not comparable to its excellent center quality, but from the actual results, the difference is not as obvious as the objective test. After all, it is said that sugar cane cannot be sweet at both ends. It is difficult for lenses of the same era to have both portability and image quality. If you want absolute high image quality, you should check out the SP 15-30mm F/2.8 Di VC USD G2.

Anti-dispersion performance test

Chromatic dispersion, also known as purple fringing, is also an important factor affecting the use of lenses. It is especially critical for ultra-wide-angle lenses that are mostly used for landscape and high-contrast scene creation.

Next, let’s take a look at the anti-dispersion performance of this lens by taking a 100% magnified slice.

17mm end aperture F2.8

17mm end aperture F8

28mm end aperture F2.8

28mm end aperture F8

It can be seen that the anti-dispersion performance of Tamron 17-28mm F/2.8 Di III RXD is still quite good. Whether at the 17mm end or the 28mm end, the dispersion is very slight in the scene of strong backlight. At this time, this problem can be easily solved by appropriately reducing the aperture, turning on the in-camera correction, or a little processing in post-production.

Vignette performance test

In the digital age, the impact of vignetting on photos has become smaller and smaller. After all, it is very convenient to correct it in the camera or adjust it later. Now it is more like a style or characteristic. In order to fully understand this lens, we will take a look at the vignetting performance of this lens through real shooting.

First, the 17mm end:

Then the 28mm end:

It can be seen that the vignetting control of the Tamron 17-28mm F/2.8 Di III RXD is a bit unrestrained. The vignetting is obvious at the 17mm end, and there is still vignetting when the aperture is narrowed. The performance is slightly better at the 28mm end. The vignetting is obvious when the aperture is wide open, but it is no longer obvious when the aperture is narrowed.

It should be said that as a lens that emphasizes portability and large aperture, it is expected that the Tamron 17-28mm F/2.8 Di III RXD has such vignetting performance. After all, many manufacturers now will play to their strengths and avoid weaknesses when designing lenses, and put some problems that can be easily solved in post-production into the camera to improve the performance of other aspects of the lens. After all, in the digital age, vignetting may be the least important lens characteristic.

Distortion performance test

Lens distortion is also a problem that can be easily solved in post-production, but unlike vignetting, if the distortion is too large, it will still affect the usable focal length of the lens, which is especially true for ultra-wide-angle lenses.

17mm:

28mm:

Judging from the test results, the Tamron 17-28mm F/2.8 Di III RXD has a certain barrel distortion at 17mm and pincushion distortion at 28mm. The distortion is well controlled and can be solved with a little correction, and the loss of viewing angle is relatively small.

More user experience

In addition to the above, the focusing performance of this lens also makes the author very satisfied: as a third-party lens, Tamron 17-28mm F/2.8 Di III RXD can support all Sony focus functions, even including the latest animal eye focus function, and the focusing speed and accuracy are the same as the original one.

F2.8 1/250 ISO1250

Tamron 17-28mm F/2.8 Di III RXD+SONY Alpha 7R Mark III

From the actual experience, the focusing experience of Tamron 17-28mm F/2.8 Di III RXD is almost the same as that of Sony GM lens. If it is not lighter, I would even forget that it is a non-original lens: the whole focusing process is extremely smooth, and the focus is always locked on the cat's eyes. We just need to press the shutter when we see the wonderful moment. On the other hand, using an ultra-wide-angle lens to take close-up photos of cats can also fully mobilize the emotions of the "master", and the interactive experience can be said to be quite pleasant.

F2.8 1/250 ISO1600

Tamron 17-28mm F/2.8 Di III RXD+SONY Alpha 7R Mark III

Of course, to achieve easy cat-sniffing, in addition to easy and quick focusing, the close-up capability of the lens is also very important: the closest shooting distance of the Tamron 17-28mm F/2.8 Di III RXD at the wide-angle end is 0.19m, and the maximum shooting ratio is 1:5.2. The closest shooting distance at the telephoto end is only 0.26m, and the maximum shooting ratio is 1:6. As a "cat-sniffing" enthusiast, switching to this lens to try ultra-wide-angle and large-aperture shooting is a very worthwhile experience.

Evaluation Summary

Looking back at the imaging products over the years, there are only two characteristics that can make consumers pay unconditionally: one is of course cheap, various entry-level cameras and kit lenses are typical representatives. After all, cost performance is always king; and the other "killer weapon" of another manufacturer is the miniaturization of the product. Nowadays, there are still many people collecting various old rangefinder lenses. In addition to the playability and sentiment, elegance and compactness are obviously also an indispensable factor.

Although I also like the Tamron 28-75mm F/2.8 Di III RXD lens, I obviously prefer the 17-28mm F/2.8 Di III RXD: compact and almost fixed focus, with a better sealed internal zoom design, excellent image quality, and outstanding close-up capability among ultra-wide-angle lenses, I even have the urge to replace the standard zoom lens in my hand with this ultra-wide-angle lens. In addition, in my mind, this lens has already reserved the candidate status of the best lens of the year.