pcmag.comWe review products independently, but we may earn affiliate commissions from buying links on this page. Terms of use. Tamron is on quite a roll with its initial batch of full-frame lenses for Sony mirrorless cameras. The 17-28mm f/2.8 Di III RXD ($899) is its second affordable f/2.8 zoom, pairing well as a wide-angle companion to last year's 28-75mm f/2.8 Di RXD standard zoom. It's an excellent value, and while its range is shorter and it's not quite as optically sublime as Sony's high-end FE 16-35mm F2.8 GM, it wins big on price and earns our Editors' Choice award in the process. Compact Wide Zoom The 17-28mm is a small zoom with a big, ultra-wide view. It measures 3.9 by 2.9 inches (HD), weighs just 14.8 ounces, and supports 67mm front filters. It's notably easier to carry than the FE 16-35mm F2.8 GM, which is 4.8 by 3.5 inches and 1.5 pounds with an 82mm filter thread. Tamron's designers took a basic, minimalist approach to the 17-28mm's aesthetics. It's finished in black polycarbonate, with rubberized focus and zoom control rings, and a classy silver accent ring around the mount. Branding is kept to a minimum, with the Tamron logo in white below the focus ring. The lens sports protection from dust and splashes, as well as fluorine protection for the front lens element. The dust and splash protection matches the similar sealing Sony includes in its cameras, and fluorine helps to keep the front element free of debris and smudges. There's no optical stabilization, so the lens relies on your camera's in-body image stabilization (IBIS) system. In practice, I was able to net handheld exposures as long as 1/3-second at 17mm with extreme care when pairing the lens with an a7R IV. At those lengthy shutter speeds, subject motion will introduce more blur than any shakiness in your hands. Close focus is available to 7.5 inches, which nets 1:5.2 life-size magnification at the 28mm focal length. You'll rarely get true macro results from such a wide lens, but you have plenty of flexibility to focus close with this one. Very Good Wide Open, Outstanding Stopped Down I tested the 17-28mm along with a couple of cameras, the 42MP a7R III and 60MP a7R IV in the field, and used the a7R IV and Imatest software to evaluate its optical performance in the lab. At 17mm f/2.8, it resolves 4,262 lines on a center-weighted evaluation, a very good result of the a7R IV's demanding sensor. The score is helped by outstanding performance in the central third of the frame (5,100 lines), but does give way to a more down-to-earth 3,500-line score, solidly in the good range, through the mid parts and periphery. There's a general uptick in resolution, to an excellent 4,800 lines averaged across the frame, with outstanding center resolution that gives way to very good results as you move toward the periphery. Resolution basically evens out at f/5.6, with the average score hitting an outstanding 5,059 lines, with edge performance that lags only slightly behind. It maintains a high level of performance at f/8 (4,764 lines) and f/11 (4,339 lines), but drops down a bit at f/16 (3,522 lines) and f/22 (2,315 lines), showing the diffraction limits of the a7R IV's sensor. At the midpoint of the zoom, 22mm, we see a slight drop in wide-open resolution, to 3,879 lines at f/2.8. Here, central resolution is outstanding (5,358 lines), but the mid parts of the frame are just acceptable (3,044 lines) and edges show noticeable softness (2,108 lines). We see some improvement at f/4, where the average resolution is close to excellent, 4,400 lines, with outstanding center resolution and very good performance up to the edge. The story is the same at f/5.6 (4,512 lines), f/8 (4,435 lines), and f/11 (4,296 lines), before dropping off as expected at f/16 (3,593 lines) and f/22 (2,346 lines). See How We Test Digital Cameras Resolution ticks down at 28mm, especially at the edges. The average score at f/2.8 is 3,607 lines, in the good range for this sensor. Again, we see the best resolution at the center (4,552 lines), good results through the mid parts (3,633 lines), and blurred edges (1,709 lines). The average improves slightly at f/4 (3,597 lines), but the overall picture is the same as at f/2.8. It's at f/5.6 where we see a significant jump in clarity, to an excellent 4,500 lines. There's still some softness at the very edges of the frame, but they're not terrible at 2,850 lines. You'll want to use f/8 for landscape shots where you need the most detail across the entirety of the image. The lens manages 4,681 lines on average and, while the edges aren't quite that good, they are still in the very good range, just shy of 4,000 lines. You'll also get good results at f/11, though there's a general softening due to diffraction at f/16 (3,705 lines) and f/22 (2,449 lines). Overall, we are very happy with the resolution the 17-28mm is able to deliver, especially when you consider its price, size, and wide angle of coverage. You do need to stop down a bit to get the absolute best results out of a 60MP sensor, but it's good practice to do so for any shot where you really need crisp corners. Vignette and distortion are well controlled. There's a very modest dimming at the corners when shooting at 17mm f/2.8, but it's not apparent at narrower apertures or when zoomed in. There's no visible barrel distortion at 17mm either, though we do see the pincushion effect at 22mm (2.6 percent) and 28mm (2.8 percent). Lightroom does include a lens profile to remove distortion, if it detracts from an image. Beyond Budget Performance Like the 28-75mm that came before it, the Tamron 17-28mm f/2.8 Di III RXD is a boon for Sony system owners shopping on a budget. It punches above its weight, delivering an f/2.8 aperture, strong optical performance, and a wide angle of view with modest zoom power for a price that's less than half that of the Sony FE 16-35mm F2.8 GM OSS. And while the 17-28mm costs less, it's built quite well, with dust and splash protection and a fluorine front coat, all features we expect from high-end optics. There are some sacrifices, of course—it doesn't reach 35mm when zoomed in after all, so you'll need to take a step or two forward to net a tighter shot. Tamron is doing a fine job filling gaps in Sony's first-party lineup. The 17-28mm and 28-75mm are both on sale now, and form the foundation of a very solid, but budget-friendly, kit. It has a 70-180mm f/2.8 Di III VXD coming next spring, rounding out the group. It also has a trio of f/2.8 prime lenses, in 20, 24, and 35mm focal lengths coming, for just $349 apiece. If you're in the market for a wide zoom for your Sony camera, the Tamron 17-28mm should be right at the top of your list, especially if you're shopping on a budget, and earns our Editors' Choice recommendation. The FE 16-35mm F2.8 GM OSS remains an excellent high-end option, but the 17-28mm is nearly as good a performer at less than half the price. It's good enough to keep up with a7R IV, and will have no problem keeping up with a 24MP model like the a7 III. Tamron 17-28mm f/2.8 Di III RXD Bottom Line: The Tamron 17-28mm f/2.8 Di III RXD delivers much better image and build quality than you'd expect from a budget lens, especially one with a wide-angle, f/2.8 design. Top Comparisons

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