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. Designed to work on full-frame cameras (but, as always, compatible with APS-C models), the 50mm f1.4 has a premium-feeling build quality and excellent tension and tactile feedback on its focus ring, and it produces sharp, bright images with little distortion. There's some softness at its narrowest aperture, f16, and off-angle wide open it has a tendency toward chromatic aberration, but these are typical problems. (Caveats: I had only a day and a half to test the lens, and due to renovations in our office I could not run my usual array of tests. If you're looking for test geekery before you buy, I suggest you check out Imaging Resources' results.)
A note about the image samples: all are raw files with no luminance noise compression, which blurs the photo slightly, so that the most detail possible is preserved. As a result, your mileage may vary.
The lens has the same design as the other fixed-focal-length lenses in the Art series: a simple, sturdy, all-metal construction with a comfortable rubberized focus ring and distance readout, plus a switch for manual/autofocus. Lots of folks have compared it to the Zeiss Otus 55mm f1.4 -- a fabulous lens to be sure, but far more expensive at close to $4,000, and it's almost twice the length not to mention somewhat heavier. I also like it better than the Canon 50mm f1.2L, which costs about $600 more (note, that's a subjective preference). I haven't tested Nikon's 50mm competitors, and as I was testing I couldn't help wishing I had a Nikon-mount version to see how it fared with an OLPF-free sensor in addition to my tests of the Canon-mount version with the Canon EOS 5D Mark III.
|Mount||Sigma, Nikon FX, Canon EF, Sony A|
|Aperture range||f1.4 - f16|
|Minimum focus distance||40 cm / 15.7 in|
|Angle of view||46.8 degrees|
|Minimum length||3.9 in/99 mm|
|Maximum length||3.9 in/99 mm|
|Weight||28.7 oz/815 g|
|Availablity||late April 2014|
At f1.4, the lens delivers excellent sharpness, though unsurprisingly it seems to perform best in the f1.8-to-f11 range. There's little distortion, I saw no vignetting, and it has nice clarity. There's some tendency to aberration at the widest apertures and softness at its narrowest, but marginal improvements in those areas make lenses more expensive.
Yeah, I wish it had image stabilization and weather sealing; I wish all lenses for OIS-based systems had it. But as a great-performing portrait lens for less than $1,000 -- and with its characteristics, it would immediately improve a good APS-C dSLR as well -- it's seriously worth considering.