Sigma EX DC HSM 10-20mm f/3.5 EX DC HSM 10-20mm

With optical quality in the top 10% of all tested lenses, the Sigma 10-20mm f/3.5 delivers seriously sharp images for Nikon APS-C cameras. Corner softness and distortion at 10mm are the main trade-offs, and there's no stabilization, but at around $479 it's an absolute steal. Buy it for landscapes and architecture, not for shallow depth of field.

We ran this lens through our usual optical benchmarks and it came out swinging: 90th percentile for sharpness. That puts it among the absolute best in its category, delivering resolving power that easily keeps up with 24MP sensors. Centre sharpness is excellent even at f/3.5, though the corners lag a bit until you stop down to f/5.6 or f/8. The 13-element optical design with four aspherical and three ED elements does heavy lifting, and flare is well-controlled thanks to the Super Multi-Layer coating. For distortion, our tests show a noticeable barrel distortion at 10mm, which is typical for this focal length but not the best we've seen; you'll likely want to apply a lens profile in Lightroom.

Autofocus, driven by Sigma's HSM motor, is quiet and adequate. It falls right in the middle of the pack at the 54th percentile, so it won't win speed contests but rarely frustrates in decent light. In dimmer settings or chasing fast-moving subjects, it can hunt a little, as some owners note. Macro performance is surprisingly decent: at 24cm minimum focus and a 76th percentile macro score, you can get creative close-ups with an ultrawide perspective, though don't expect true 1:1 reproduction. And a note on stabilization: the lens lacks optical image stabilization, which is par for the course in this class but worth knowing if you shoot handheld in low light a lot.

Against the Viltrox Air 15mm f/1.7 E-Mount, the Sigma gives up about two stops of light but offers a zoom range, which is huge for composition flexibility. The Viltrox is sharper wide open and better for astro, but it's a prime and restricted to Sony E-mount. Compared to the Nikon NIKKOR Z 18-140mm f/3.5-6.3 VR, the Sigma is less versatile at the long end but dominates in wide-angle sharpness and constant aperture. And while the Canon RF 28-70mm f/2.8 is a completely different beast, its price and full-frame design highlight just how much value the Sigma packs. If you're on Nikon F APS-C, the Sigma remains the go-to affordable ultrawide zoom.

Pricing for this lens varies wildly across vendors: we spotted it at a reasonable $479 on Newegg, while some listings push as high as an absurd $80,255. The real story is that for around $500, you're getting optics that rival lenses costing twice as much. Considering the 90th percentile sharpness and the solid build, the Sigma 10-20mm f/3.5 offers some of the best price-to-performance we've seen in an ultrawide zoom. If you find it at the lower end of that price spread, it's a no-brainer.

Optical quality on the Sigma 10-20mm f/3.5 is a standout, landing in the top 10% of all lenses we've tested. That translates to crisp, detailed images across the frame, making it a favourite among landscape and architecture shooters on a budget. At its core, this is an f/3.5 constant aperture ultrawide zoom built for Nikon APS-C DSLRs, and it delivers sharp results that often rival much pricier glass. But the numbers tell a more nuanced story: the aperture itself, while constant, sits in just the 18th percentile, which means it's relatively slow, and bokeh is practically nonexistent at the 12th percentile. So if you're after dreamy backgrounds, this isn't your lens. Still, for wide vistas and tight interiors, the image quality is hard to beat at this price.

Users agree, giving it a 4.7 out of 5 from over 6,000 reviews and an 85/100 sentiment score. The recurring theme is value: you get sharpness, a solid build, and a useful focal range without emptying your wallet. However, corners soften at wider apertures and distortion at 10mm is very real, so post-processing is often part of the workflow. That said, if you know what you're getting into, the Sigma 10-20mm f/3.5 is a lens that punches above its weight class.

If you need fast, reliable autofocus for action or sports, look elsewhere—the AF is middle-of-the-road at best. Portrait shooters or anyone craving subject isolation should stay away; the bokeh is nearly nonexistent and the aperture isn't fast enough to blur backgrounds. And if you're on a full-frame Nikon, this lens simply won't cover your sensor, so invest in an FX ultrawide instead. Finally, if handheld low-light shooting is your main gig, the lack of stabilization makes it a tough sell.

The Sigma 10-20mm f/3.5 isn't perfect, but it nails the fundamentals for landscape and architecture shooters. Its optical performance is superb for the price, and the constant f/3.5 aperture gives you consistency. Just know that you'll be correcting distortion and working around corner softness at wide apertures. For less than $500, it's one of the best value ultrawide lenses we've tested, and the 4.7-star user rating backs that up. If you can live without stabilization and don't need bokeh, this lens deserves a spot in your bag.