Sigma Art 10-20mm f/2.5 EX DC HSM 10-20mm

The Sigma 10-20mm f/2.5 EX DC HSM is a rare bright ultrawide zoom for Nikon DX DSLRs with excellent optics and a constant f/2.5 aperture. It's sharp, relatively light, and includes a useful bundle of accessories. Just know it lacks stabilization and weather sealing, and it's strictly for APS-C bodies.

Sharpness is where this lens earns its keep. Center sharpness is excellent wide open at f/2.5, and the corners catch up nicely by f/4. For real estate or architectural work, that means you can shoot handheld in dim rooms without everything turning to mush. The 9-blade diaphragm helps keep out-of-focus highlights looking natural, which matters more than you'd think when you're shooting at 10mm and something in the foreground drifts out of focus.

Autofocus performance lands in the 54th percentile, which is about average for DSLR-era HSM lenses. It's reliable in good light but can hunt a bit in low contrast situations. For video work, the lack of stabilization (37th percentile) means you'll want a tripod or a camera body with IBIS if you're shooting handheld. The minimum focus distance of 240mm lets you get reasonably close to subjects, and the 1:6.6 magnification ratio is enough for some creative wide-angle detail shots, though this isn't a macro lens by any stretch.

Compared to the Tamron Di III 17-70mm f/2.8, the Sigma goes significantly wider and is a stop faster, but the Tamron has stabilization and a more versatile zoom range for general shooting. The Nikon NIKKOR Z 17-28mm f/2.8 is a full-frame mirrorless lens, so it's not a direct competitor unless you're planning a system switch, but it shows where the industry went after this Sigma was designed. The Panasonic Leica DG Vario-Elmarit H-ES12035 and Sony E PZ 16-50mm f/3.5-5.6 OSS are both slower and aimed at different mounts, so they're not really in the same conversation for a Nikon DX shooter who wants speed.

The Canon RF 28-70mm f/2.8 IS STM is a full-frame standard zoom, so it's a completely different beast. The real takeaway here is that if you're still shooting a Nikon DX DSLR and want an ultrawide zoom that can handle low light without a flash, the Sigma 10-20mm f/2.5 is basically in a class of one. The closest alternatives are all f/3.5 or slower, and that extra two-thirds of a stop matters more than the spec sheet suggests when you're shooting handheld at dusk.

Pricing hovers around $634 to $645, which puts this lens in a weird spot. It's more expensive than most used ultrawide zooms for DSLRs, but you're paying for that f/2.5 aperture, and there's really nothing else like it for Nikon DX bodies. The bundle sweetens the deal with a filter kit and cleaning supplies, so you're not nickel-and-dimed on accessories. If you need the speed and don't want to switch to a full-frame system just to get a bright ultrawide, this is a solid value. But if you're mostly shooting at f/8 on a tripod, you can save money with a slower lens and never notice the difference.

If you're hunting for an ultrawide zoom for a Nikon DX DSLR, the Sigma 10-20mm f/2.5 EX DC HSM Art lens is one of those lenses that makes you do a double take. A constant f/2.5 aperture on an APS-C ultrawide? That's genuinely unusual, and it's the main reason this lens still gets attention years after its release. The 15-30mm equivalent range covers everything from dramatic landscapes to tight interior shots, and the bright aperture gives you way more flexibility in low light than the typical f/3.5-5.6 kit zooms most people start with.

Build quality is solid but not flashy. The HSM autofocus motor is quick and quiet, though it's not going to blow anyone away by modern mirrorless standards. At 465g, it's surprisingly light for a lens with this much glass inside. The 77mm filter thread is a nice touch too, since it matches a lot of pro-level lenses and means you don't need a whole separate set of filters. Just keep in mind this is strictly an APS-C lens, so full-frame shooters need to look elsewhere.

Optically, this lens sits in the 90th percentile in our database, which is impressive territory. The combination of four aspherical elements and three ED elements keeps distortion and chromatic aberration well under control for such a wide zoom. Bokeh quality also ranks in the 89th percentile, which isn't something you typically care about on an ultrawide, but it's nice to have when you're shooting close-up details at f/2.5. The Super Multi-Layer Coating does its job cutting down flare, though you'll still want the included lens hood when shooting anywhere near the sun.

Travel photographers and casual shooters should probably look elsewhere. The lack of stabilization and weather sealing makes this lens less ideal for on-the-go shooting in unpredictable conditions, and the 47.4 travel score in our database reflects that. If you're mostly posting to social media and don't need the f/2.5 aperture, a lighter stabilized zoom or even a wide prime will serve you better. Anyone planning to switch to Nikon Z mirrorless in the near future should also skip this and put the money toward native Z glass instead.

Should you buy this? If you're a Nikon DX DSLR shooter who regularly finds yourself wishing your ultrawide was just a bit brighter, yes. The constant f/2.5 aperture is the whole story here, and it delivers. Real estate photographers, event shooters working in dim venues, and astrophotographers will all appreciate the extra light gathering. The optical quality backs up the spec sheet, with sharpness that holds its own against lenses that cost a lot more.

But if you mostly shoot landscapes at f/8 on a tripod, or you're thinking about moving to mirrorless in the next year or two, this lens is harder to recommend. The lack of stabilization and weather sealing means it's not the best travel companion, and the limited reviews make it harder to gauge long-term reliability. For the right person, though, it's a gem.