This is the first Sigma 50mm f/1.4 prime lens for 4/3 DSLRs, a tele photo lens in the focal length of 100mm equivalent to portrait lens in medium distance. A superb lens of optical quality and design, fast focus in silent with HSM.

Fast aperature in f/1.4 with beautiful bokeh; Short lens barrel and well balance of weight by hand-held with camera body; Fast focus speed in silent with HSM

I use the lens mainly for low-light and night photography in the Yorkshire Dales. It's immensely heavy for a 50mm lens, but the optical quality is outstanding - pin sharp from corner to corner from f2 upwards. I don't mind the extra weight when I can get such high quality images.

Consistent Output; Durable; Rugged; Sharp Focus; Strong Construction

Heavy

This is an excellent lens, with crisp and clear imaging. Made of solid materials, this thing feels nice in hand and on camera. I was a bit put off by the chunky lens cap, but I usually replace those anyway. Other reviewers have written detailed reviews, so I won't get into that here.

Amazing lens! I absolutely love it - everything from build quality, Bokeh, image quality, this lens absolutely shines!

I was scared after reading reviews that it has some back focus problem... but it was fine! Plus, if there's any problem, you can always return and get a new one.

Consistent Output; Durable; Easily Interchangeable; Nice Bokeh; Rugged; Strong Construction

Heavy

This lens has opened some doors for me with its f1.4 capabilities. I was trying to decide between this and the two more affordable canon 50mm lenses. Ultimately I sold myself on this output quality from this lens.

Low Light; Nice Bokeh; Rugged; Sharpness; Strong Construction

Inconsistent focus

Every camera film or digital has set a benchmark. The images are truly world class and delivers excellent contrast and sharpness even in low light conditions.

Bought this lens for the great bokeh and sharpness. I tried it on Nikon D700 and quiet happy with a result. The glass is heavy and massive ,but the filling is right on.Fast and furious :)

This telephoto macro lens was the first lens I purchased for my DSLR. It was intended for insect macrophotography, and has not disappointed. At around f8, the lens is very sharp; it is softer wide open, but this is not a problem for macros as the depth of field at f2.8 is too shallow anyway.

Sharp image and 1:1 magnification

Clunky focusing system

Similar in size, features, and price (though not format) to Sigma's 30mm f/1.4 high-speed "normal" prime for DSLRs with APS-C sensors, this 50mm full-framer ($500, street) also belongs to Sigma's EX family of pro-quality glass.