Sigma 24-70mm f/2.8 EX DG Macro - Sigma SA, Canon EF, Nikon F, Sony A, Pentax K Mount

The Sigma 24-70mm f/2.8 EX DG Macro is a standard zoom lens for full-frame DSLRs that combines a constant f/2.8 aperture with a respectable close-focusing capability. While not a true 1:1 macro, it offers a 1:3.8 magnification ratio, making it highly versatile for general-purpose photography and detail shots. The 'DG' designation ensures that optical coatings are optimised for digital sensors to reduce flare. Common points to check on a used 24-70mm EX DG include the zoom tension; these lenses can sometimes develop 'zoom creep' or stiff spots over time. The AF/MF clutch mechanism, if present on the specific mount version, should be tested for smooth switching. SDS checks the optics for haze or fungus and ensures the aperture stays oil-free. The lens barrel’s 'EX' finish is also inspected for the typical peeling or tackiness associated with heavy use.