The pictures below illustrate the angles of view on 35mm full frame and APS-C (1.6x crop) camera bodies. Our observations indicate that the focal length is noticeably shorter than the specified 50mm (probably closer to 47mm):

Class-leading image quality; Relatively low vignetting even at wide apertures on full frame; Reasonably fast and positive autofocus; with full-time manual override; Very good build quality

Large and heavy for a 50mm F1.4; Expensive

Gary Wolstenholme takes a look at this fast f/1.4 aperture standard lens suitable for full frame and crop sensor DSLRs.

Excellent sharpness in the centre at most apertures; Low vignetting; 77mm

Maybe a little softer than I'd hoped at f/1.4; Heavier than any other 50mm f1.4 lens; Bigger than any other 50mm f/1.4 lens

Performance & handling Prime lenses are about as simple as can be in terms of handling. You have just two controls – the focus ring and (depending on your lens mount) the AF/MF switch.

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 weary to buy this lens due to many review of the autofocusing not behaving. I bought 2 copies to hope that one would work with my camera. I noticed within the two copies that one was softer than the other. The autofocus is also not super at low light situations.

Yes, I would recommend this to a friend

Fast / accurate auto-focus; Nice Bokeh; Rugged; Strong Construction

Tight manual focus right

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.

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

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