The Sigma 28-45mm f/1.8 DG DN Art is the world's first constant f/1.8 zoom for full-frame mirrorless cameras, announced on 3 June 2024 and released on 20 June 2024 for Sony E and L-Mount. It sits in Sigma's flagship Art line as a statement piece: a zoom designed to genuinely replace a set of fast primes between 28mm and 45mm, and a spiritual full-frame successor to Sigma's famous 18-35mm f/1.8 for APS-C.
The optical formula uses 18 elements in 15 groups with five SLD and three aspherical elements, an 11-blade rounded diaphragm and an 82mm filter thread. Autofocus is handled by Sigma's HLA linear motor, and the design is fully internal-zooming and internal-focusing, which keeps the balance constant for gimbal use. There is no optical stabilisation, so it relies on in-body stabilisation. It carries a clicked, de-clickable aperture ring, AFL button, zoom lock and dust- and splash-resistant construction, and weighs 960g at 151.4mm long. Sigma pitches its cross-frame sharpness as prime-like even wide open at f/1.8.
Its significance is simple: nothing else does what it does. For low-light event shooters and hybrid video users it offers prime-level speed with framing flexibility, and reviewers such as PetaPixel and Fstoppers rated wide-open performance as excellent. The limited 1.6x zoom range is the trade-off, so used demand comes chiefly from wedding, documentary and video shooters who would otherwise carry 28mm, 35mm and 45mm primes. On the UK used market it is relatively scarce compared with mainstream zooms, which supports resale values.
Used-buying checks: shoot it wide open at f/1.8 at both ends of the zoom against a detailed flat scene to confirm no decentring, since the whole point of this lens is wide-open sharpness. Test the aperture ring in both clicked and de-clicked modes, check the AFL button and zoom lock, and confirm the HLA motor is silent in video AF. As a 2024 release most copies will be lightly used, but check the 82mm front thread and hood mount for cross-threading. Confirm firmware is current (updatable in-camera on L-Mount or via Sigma USB Dock UD-11 on E-mount only via supported bodies). UK new retail is around £1,249-£1,349, so judge used pricing against that; there are no known systemic faults reported to date.