The 50mm F1.4 EX DG HSM is the latest design from independent lens maker Sigma, announced in March 2008. It's a rare example of what is rapidly becoming an endangered species; an all-new, large maximum aperture, fixed focal length 'prime' lens, and (like Sigma's 30mm F1.4 DC before it) a hugely welcome addition to a market in danger of becoming saturated by identikit slow zooms. The 50mm focal length makes it a classic 'standard' lens for 35mm full-frame cameras, while on DSLRs with smaller format sensors it acts as a short 'portrait' telephoto, with an equivalent angle of view ranging from 75mm (on 1.5x 'DX' format) to 100mm (on Four Thirds DLSRs). The fast maximum aperture offers several key advantages over zooms, including the ability to isolate a subject by selectively blurring the background, the option to shoot in low light whilst maintaining reasonably high shutter speeds (ideal for indoor photography without flash), and the provision of a bright viewfinder image for composition.