The 'EX' in the name denotes this lens's superior optical and build quality, the 'DG' means that it's optimised for the smaller sensor areas of most DSLRs but will still work on a full-frame camera, and the 'HSM' stands for 'Hyper-Sonic Motor', Sigma's proprietary high-speed autofocus technology.

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

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.

Required factory focus recalibration. Still slightly front focusing, most noticeable wide open when there's little DOF. Re calibration process was painless. I paid to ship lens and camera body to sigma in Long Island NY, and they took it from there. Got it back in a few working days.

Image Quality Bokeh Fast; Nice Bokeh; Strong Construction

Blurry Focus

My reaction to every fast lens Sigma release seems to be "I can't believe something this good costs less than $1,000." A new favorite -- the 50mm f1.4 DG HSM -- joins Sigma's Art series of lenses, which already includes two of my all-time sub-$1K favorites, the 35mm f1.4 and 18-35mm f1.8 .

The Sigma 50mm f1.4 lens is a well-designed lens that performs very well for its price

It would be nice if it had image stabilization

While it's not cheap, the Sigma 50mm f1.4 lens provides great value for the money.

It would be nice if it had image stabilization

Purchase use.Very good from F/2.2. Front focus 1.4-2.0. After 2.2 have litle back focus. From f4 focus is perfect. Work very well in life view with Canon 60D. Mutch better than Canon 50/1.8.Very happy.

Consistent Output; Durable

Very good

One word for the product: AWESOME Let me list out the pros and cons below for better readability. I am so excited about this product that my words will just mix-up. PROS: 1. SUUUUUPERIOR quality images. DAYUMMMN sharp.

I'm a wedding photographer, so fast primes are a must for me, especially during indoor ceremonies/receptions, and the Sigma 50mm f/1.4 ART lens for Sony did not disappoint! Physically, the lens has a clean, simple, and beautiful build.