The Sigma 50mm F1.4 EX DG HSM is a fast prime that behaves like a classic 'normal' lens on full frame, and a short telephoto portrait lens on APS-C cameras. It offers impressive central sharpness at large apertures, coupled with unusually low vignetting for its class due to its oversized optics; however this also means it’s rather large. Build quality is excellent, and the lens is available in versions to fit every SLR on the market.