The Sigma 50mm f1.4 DG HSM Art is a standard prime lens that’s available in Canon, Nikon, Sigma or Sony A-mounts. 50mm lens delivers ‘normal’ coverage on a full-frame body and is ideal for general-purpose use, and becomes equivalent to 75mm on APS-C bodies (80mm on Canon), making it ideal as a short telephoto for portraiture. The focal length may be normal, but the performance is anything but. Announced in January 2014, it joins Sigma’s growing ‘ART’ series of high performance lenses which so far have greatly impressed us in tests. The 50mm ART is also compatible with Sigma’s USB dock for fine-tuning or firmware updates, and if you change bodies, you can pay to have the mount swapped for your new system.
The ART 50mm f1.4 DG HSM offers the same focal length and aperture as the existing Sigma non-ART version, but sports a completely new optical design, more complex and much larger, not to mention three to four times more expensive depending on region. It’s also typically two and a half to three times more than the standard 50mm f1.4 lenses from Canon and Nikon, although roughly two thirds of the price of the top-end Canon 50mm f1.2 and Nikkor 58mm f1.4.
So the new Sigma 50mm ART is positioned roughly between standard 50mm f1.4 lenses and the top-end models from Canon and Nikon in price. The big question then is how does it to compare to those below and above it in price? Does it offer a sufficient step-up from normal 50mm f1.4 lenses to justify the price, and does it give the pricier models a run for their money? To find out, Thomas and Gordon teamed-up to give the Sigma 50mm ART a real workout, with Thomas comparing it against the Nikkor 50mm f1.4 and the mighty Zeiss Otus 55mm f1.4 on his Nikon D800, while Gordon compared it against Canon’s 50mm f1.4 and 50mm f1.2 on an EOS 6D. Read on to find out if this is the ultimate 50mm lens!
To start with, here’s how the Sigma 50mm ART looks next to some key rivals. I’ll start by picturing it flanked by Canon’s cheaper EF 50mm f1.4 USM on the left and the more expensive EF 50mm f1.2L USM on the right. Notice how it’s comfortably larger than either.
Next up the Sigma is flanked by the standard 50mm f1.4 lens from Nikon on the left and the mighty Zeiss Otus on the right.
Facts from the catalog
As usual I’ll have a look at the technical data first. I’ve rated the features with a [+] (or [++]), when it’s better than average or even state of the art, a  if it’s standard or just average, and [-] if there’s a disadvantage.
Most features are compared to Sigma’s own 50/1.4 EX DG HSM from 2008 which I’ll simply refer to as the “smaller brother”.
Size (diam. x length): 85 x 100 mm (3.4 x 3.9 in.). Much longer than its smaller brother at 85 x 68 mm. Put on the lens-shade and it grows to 145mm which looks quite intrusive if you point it at someone. [-]
Weight: 815 g (28.7 oz). Over 300g heavier than its older brother. Yet the Otus, at 970g, is heavier still. [-]
Optics: 13 elements in 8 groups. This design is even more complex than from the Otus which uses 12 elements in 10 groups. To avoid negative effects from that many optical elements the coating better be good. The Art’s smaller brother has 8 elements in 6 groups. 
Closest focus distance/max. magnification: 40cm (1.3 ft.) / 1:5.6. Its smaller brother offers 45 cm / 1:7.4. 
Filter-thread: 77mm just like its smaller brother which is standard for many pro-lenses. 
Image stabilization: No, same as any other fixed focal large aperture lens from Nikon, Canon or third parties below 200mm focal length. 
AF: HSM (hyper sonic motor), so it does work on camera-bodies that don’t have their own AF-drive. Manual-focus override by simply turning the focus ring. [+]
Covers full frame/FX or smaller = very good [+]
Price: around 900 EUR new (incl. 19% VAT). This is clearly not the cheapest 50/1.4 lens you can buy for a Canon / Nikon / Sony. But it’s still comfortably cheaper than the top-end models from the camera manufacturers. Its smaller brother is around 430 EUR. 
Comes with a nice semi-soft lens-case that is well padded but has no strap. Lens-shade is included, reversible for transport, rear and front lens-caps are similar to Nikon’s although still not as well designed. 
Distance information is relayed to the camera, so the Nikon body (and CLS flash-system) can do all the advanced exposure-related stuff with this lens. [+]
Aperture ring: No, just like all competitors with AF. 
Sealing: No. Just like its smaller brother. 
The score in the “features-department” is 2[-]/8/3[+]. On paper only the large size and weight is on the negative side, although for the money some weather sealing would have been nice.
There’s no shortage of 50mm lenses on the market, and many camera and lens companies actually offer a choice of apertures too. The f1.8 versions are definitely worth considering: they are smaller, lighter, cheaper, less obtrusive and often deliver similar – or even superior – image quality than their bigger brothers. The loss of 2/3 of a stop may not be as relevant as the marketing literature wants you to believe. But if you absolutely want or need f1.4 (or brighter) then you have the following alternatives:
– From Nikon there are the AF-S 50/1.4G which can currently be had for 340 EUR and the much more expensive 58/1.4G (see my Nikon AF-S 58mm f1.4G review). There’s also Nikon’s old AF 50/1.4D still on offer and it’s the cheapest of the bunch. But from what I’ve seen in other reviews the 50/1.4G seems the better choice (see my Nikon AF-S 50mm f1.4G review).
– Canon offers the EF 50mm f1.4 USM at a lower price or the EF 50mm f1.2L USM at a higher price (see Gordon’s Canon EF 50mm f1.2L USM review). Sony has the AF 50/1.4 and the AF 50/1.4 ZA SSM.
– Then there are other alternatives if you’re happy to manually focus. But since the depth of field at f1.4 is pretty shallow make sure that your focusing capabilities are up to that challenge! If so you can choose from the Zeiss ZF.2 Planar T* 50/1.4 at 600 EUR and the Voigtländer SL II Nokton 58/1.4 at 500 EUR. Both lenses perform very well in the image center according to reviews but the Zeiss seems very soft in the FX-corners and the Voigtländer produces a nervous Bokeh. The 800 pound gorilla in this group of MF lenses is the new Zeiss Otus 55/1.4, and I wish it cost 800 pounds! At a price of 3500 EUR and over 900g weight plus a completely different optical design than other “normal” lenses it sets a new benchmark on optical performance in this group. Read my Zeiss Otus 55/1.4 review.
Focus and build quality
Focus accuracy and repeatability is critical to consistently produce sharp shots, especially with large aperture primes. Repeatability (the accuracy of focus on the same subject after repeated focus-acquisition) of this lens is very good with only very slight variations and no real outliers over a series of 40 shots. AF consistency was measured with Reikan FoCal at 97.6%. The lens focuses in around 0.6 sec from infinity to 50 cm, which is good. Its older brother does this in 0.5 sec.
The focus ring has no slack/play between its movement and the focus-action and a throw of around 90 degrees, which is the same as with its older brother which is very short for accurate focus wide open. The focus ring has a 2.5 cm wide finely ribbed rubber surface that is easy to grip and moves smoothly albeit a bit tight. The focus-ring turns the same way as on Canon lenses. Unfortunately that is the opposite direction to what Nikon users have come to expect. AF-operation is very quiet from the outside. If you record video with the built-in microphone the focus-movement produces only a slight “clack” at the start and the end of the movement and the AF-drive itself is also not too annoying. Focus breathing is clearly visible: things in the background become larger the closer you focus.
The lens needed some AF micro adjustment for optimal AF on my D800 depending on the distance from the subject. Fortunately the lens can be adjusted for four different distance ranges (around 40cm, 70cm, 1.5m and infinity) if you get Sigma’s USB dock and use their optimization pro software. But beware: this is a pretty tedious process. If you only use the AF micro adjustment in your camera then go for the adjustment which best matches your typical shooting distance with this lens.
The lens has no weather sealing which is a shame considering its premium status. Shaking the lens produces little noise, the lens-shade sits tight, and the general impression of the metal and plastic build quality is pretty high.
Now it’s time to check out some results in my Sigma 50mm ART quality pages – there’s five pages of results, so be sure to check them all out before heading to my Sigma 50mm ART sample images! Or if you’ve already read enough, skip straight to my verdict!