Sigma 17-50mm f/2.8 EX DC OS HSM (FLD) Autofocus APS-C Lens for Select Nikon F-Mount Cameras {77}

Sigma's fast standard zoom built for APS-C shooters

The 17-50mm f/2.8 EX DC OS HSM gives APS-C Nikon shooters a constant f/2.8 aperture across a focal range that covers wide-angle establishing shots at 17mm through short telephoto compression at 50mm. On a crop sensor, that translates to roughly 25.5-75mm equivalent, which is the kind of working range that handles most day-to-day shooting without requiring a lens swap. The Hyper Sonic Motor autofocus is quiet and fast enough to keep pace with moving subjects, and the built-in Optical Stabilization adds another layer of confidence when light drops.

The FLD glass elements reduce chromatic aberration and color fringing, which matters most when shooting in high-contrast scenes. The 77mm filter thread is a standard size that fits most polarizers and ND filters already in a working photographer's kit. EX build quality means tighter tolerances and better materials than Sigma's entry-tier glass. For a lens that sits at the center of your shooting day, that durability counts.

Who It's For

Event and wedding photographers working APS-C bodies will find the constant f/2.8 aperture reliable through reception lighting that varies from dim to dark. Street and documentary shooters benefit from the HSM's quiet autofocus operation and the OS system when handholding at slower shutter speeds. Travel photographers carrying a single-body kit get a focal range wide enough for interiors and long enough for environmental portraits. Videographers shooting on crop-sensor Nikon DSLRs get smooth, near-silent autofocus without the focus breathing and noise of older screw-drive designs.

Key Features

• Constant f/2.8 aperture across 17-50mm focal range
• Hyper Sonic Motor autofocus for fast, quiet focusing
• Optical Stabilization provides 2-3 stops of handheld correction
• FLD glass elements minimize chromatic aberration in high-contrast scenes
• EX build quality with tighter tolerances and reinforced construction
• 77mm filter thread for standard polarizer and ND filter compatibility
• APS-C optimized design delivering 25.5-75mm equivalent on crop sensors

FAQ

What's the equivalent focal length on a Nikon APS-C body?

17-50mm becomes approximately 25.5-75mm in 35mm terms on a crop sensor, giving you a wide-angle-to-short-telephoto range without swapping glass.

Does this lens work with full-frame Nikon cameras?

No. The DC (APS-C format) design is optimized for crop sensors only; it will vignette heavily and isn't supported on full-frame bodies.

How fast is the autofocus?

The HSM (Hyper Sonic Motor) is quiet and responsive enough for moving subjects, though it's not as rapid as modern AF-S or mirrorless motors.

Can you stack filters on the 77mm thread?

Yes. 77mm is a standard filter size, so stacking polarizers, ND filters, or other common glass is straightforward without stepping up or down in size.

What does the OS (Optical Stabilization) buy you?

2-3 stops of handheld stability depending on focal length and how steady your technique is. Helps at slower shutter speeds in lower light without bumping ISO.

What's the build quality difference between EX and non-EX Sigma glass?

EX means tighter tolerances, better materials, and more durable construction overall. The tradeoff is weight and price, but it's worth it if you're shooting daily.

How does FLD glass reduce color fringing?

FLD elements compensate for chromatic aberration at high contrast edges (dark branches against bright sky, for example), keeping color separation minimal without needing post-processing.