Sigma"s 50mm F1.4 EX DG HSM is high quality, professional optics and you"ll know it the minute you pick it up. In the past few years, camera manufacturers have overlooked the need for a reasonable fast prime lens that is compact enough for everyday use, yet provides the necessary image quality to meet the highest expectations. Now, with the advent of the APS-c cameras, the long popular 50mm focal length takes on double duty as a portrait length lens of approximately 90mm on most of the small chip cameras. At a fraction of the size, weight and cost of comparable lenses, this is a lens that you might have on your digital SLR at all times.