The latest 50mm is unusually large and expensive for its type; indeed its $950 / £850 price tag suggests Sigma is aiming at users who might otherwise choose the Nikon AF-S Nikkor 58mm F1.4G or Canon EF 50mm F1.2L USM. It bears a distinct family resemblance to the company's 35mm F1.4, but if anything is slightly larger, with a 100mm / 4" long barrel and 77mm filter thread. Its complex optical formula of 13 elements in 8 groups isn't based on a conventional double-Gauss design, like most 50mm primes are, but instead is of the retrofocal type.
This set of characteristics, along with Sigma's recent track record of making impressive optics, means that the 50mm F1.4 Art has inevitably invited comparison to the astounding Zeiss Otus 1.4/55 - quite possibly the sharpest lens we've yet seen. However given that lens's $4000 price tag, it seems a little optimistic to expect quite the same qualities. But the Sigma offers autofocus via a ring-type ultrasonic motor (with full-time manual override), which means it wins out on practicality.
Headline features
- 50mm focal length
- Fast F1.4 maximum aperture
- Ring-type ultrasonic autofocus motor with full-time manual override
- Internal focus design
- Will be available in Canon EF, Nikon F, Sony Alpha, and Sigma SA mounts
Size and Design
The 50mm F1.4 Art is quite different from any previous autofocus 50mm F1.4 for full frame, and much more similar in size and optical design to a typical 35mm F1.4 lens. This means it's almost twice the length, and three times the weight of the more traditional double-Gauss designs from Canon and Nikon. It's also substantially larger than either the older Sigma 50mm F1.4 EX DG HSM, or the Sony Carl Zeiss Planar T* 50mm F1.4 ZA SSM, both of which are pretty sizeable for a 'fast normal' prime. |
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| Here you can see how much larger the Sigma 50mm F1.4 is compared to a traditional design the Canon EF 50mm F1.4 USM. For some potential buyers, this extra bulk may be reason enough to discount the Sigma. | Mount the 50mm F1.4 on a full frame SLR, though, and it handles perfectly well. Its bulk will probably discourage any attempt at one-handed shooting though. |
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Lens test data
The Sigma's price means that we expect it to be used mainly on full frame cameras, so we're going to concentrate on analysing this aspect of its performance in this initial short report. As, usual, though, we're also making data for APS-C available - click here to see test results from the EOS 7D. We're looking at a Canon-mount lens simply because that's the first version to go on the market (and therefore be available to test).The Sigma performs exceptionally well on full frame; it may not quite match the Zeiss Otus 55mm F1.4 for sharpness at maximum aperture, but it outperforms anything else in its class for which we have data, including Nikon's recent AF-S Nikkor 58mm F1.4G. Particularly remarkable is its extraordinarily low distortion.
| Sharpness | Sharpness is very impressive indeed. At F1.4 it's unusually high for a 50mm prime, and deteriorates only slightly from the centre to the corners. By F2.8 it's extremely sharp right across the frame, to the extent that these measurements are probably limited more by the EOS 5D Mark III's 22MP sensor than by the lens. There's hardly any change on stopping down to F8, but beyond this the softening effect of diffraction inevitably kicks in. However even F16 should give entirely usable results when extended depth of field is necessary. |
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| Chromatic Aberration | Lateral chromatic aberration is extremely low. There might be a little green/magenta fringing right in the corners of the frame if you really go looking for it, but it's unlikely to be problematic in normal use. |
| Vignetting | Vignetting is kept well under control, at just 1.5 stops wide open, which is very respectable for an F1.4 prime. The falloff profile is rather gradual too, which tends to make any vignetting less visually objectionable. Stop down to F2, and any vignetting effectively disappears. |
| Distortion | Distortion is astonishingly low, with just the barest hint of pincushion stretching at the extreme corners of the frame. This marks the Sigma apart from other 50mm full frame primes, which all tend to show some degree of barrel distortion. |
To really appreciate just how good the Sigma is, we need to look at how it compares to other similar lenses (click on the yellow links to open up comparison widgets in a new window). The benchmark right now is the Zeiss Otus 1.4/55, and while the Sigma can't quite match it for outright sharpness right across the frame wide open, it's extremely close. Indeed when tested on the 22MP Canon EOS 5D Mark III, it's clear that the MTF measurements for both lenses are being limited as much by the camera's resolution than the lens itself, even at maximum aperture. In other respects the gap is also very narrow, with the Sigma having slightly higher chromatic aberration, but less vignetting and lower distortion than the Zeiss.
Now let's take a look at some other premium fast primes. The Sigma is simply much sharper at maximum aperture than the Nikon AF-S Nikkor 58mm F1.4G (despite being tested here on a lower-resolution camera), and has far lower distortion too. We see a similar story compared to the Canon EF 50mm F1.2L USM; the Sigma is sharper, has notably lower later chromatic aberration, and of course practically no distortion at all. It's also worth noting that the 50mm outperforms its much-lauded sibling, the Sigma 35mm F1.4 DG HSM | Art, in every attribute we're measuring here.
Compared to more-conventional 50mm F1.4s, the Sigma also shines. It's substantially sharper than either the Nikon AF-S Nikkor 50mm f/1.4G or the Canon EF 50mm f/1.4 USM at apertures larger than about F5.6, and has lower chromatic aberration, vignetting and distortion than either of these lenses too. It's much the same story with Sigma's previous 50mm F1.4 EX DG HSM; the new model is much sharper wide open, and clearly better in the corners of the frame at intermediate apertures. Of course these lenses are all much less expensive - but this shows why.
Summary
From the lab test results, the Sigma 50mm F1.4 DG HSM | Art goes a long way to living up the high expectations that have been placed on it. Indeed it's one of the best-performing lenses of its type, bettered only by the much-more expensive Zeiss Otus 1.4/55 - and even then, not by all that much. We'll be expanding this report into a full review as soon as possible, in which we'll be analysing its real-world behaviour and looking at the less-tangible aspects of image quality, but just right now, we're very impressed indeed.Image Samples Gallery
We've had an early sample of the 50mm F1.4 DG HSM for a couple of days, long enough to put together a quick initial samples gallery. We've concentrated on large-aperture shots to show sharpness and bokeh, but have also thrown in several images shot at smaller apertures too.There are 31 images in the samples gallery. Please do not reproduce any of these images on a website or any newsletter / magazine without prior permission (see our copyright page). We make the originals available for private users to download to their own machines for personal examination or printing (in conjunction with this review), we do so in good faith, please don't abuse it.
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Where to Buy
$949.00 Amazon Sigma 311205 50mm F1.4 DG HSM Art Lens for Sony Alpha Cameras*free shipping (Sony)
$949.00 Amazon Sigma 311110 50mm F1.4 DG HSM Art Lens for Sigma SA Cameras*free shipping (Sigma)
$949.00 Amazon Sigma 311306 50mm F1.4 DG HSM Art Lens for Nikon Cameras*free shipping (Nikon)
$949.00 Amazon Sigma 311101 50mm F1.4 DG HSM Art Lens for Canon Cameras*free shipping (Canon)
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