Sigma 50mm f/1.4 DG HSM | A review

‘What is the best lens I can get for my camera?’ It is a simple question, and one that most photographers want to know, but the answer is complicated and depends entirely on your subject. As far as all-round performance and versatility go, however, you can’t go far wrong with a good 50mm optic.

With a field of view said to closely match that of human vision, the 50mm focal length is suitable for a wide range of subjects, from portraits and travel to landscapes to documentary. It is no surprise that the 50mm lens is often the second optic that many entry-level photographers buy, especially with a 50mm f/1.8 lens costing as little as £85.

In fact, 50mm lenses can become a little like a drug, and for some, owning one will never be enough. These photographers will continually search for new examples of the 50mm lens, in different versions, ages and lens mounts, with each having its own particular quality.

I freely admit to being one of those people. One of my favourites is the Nikkor F 50mm f/1.4 that, when wide open, has low contrast, is soft focus and has a tendency to flair, yet it looks great photographing certain subjects.

Of course, lens design has moved on leaps and bounds since this 1960s example, and the latest Sigma offering, the Sigma 50mm f/1.4 DG HSM | A, shows just how far things have come.

This new lens has aleady been the subject of a great deal of hype. We heard whispers from Sigma months ago of just how good its new lens was going to be. Obviously, we take any comments from manufacturers with a large pinch of salt, but claims of it matching, and bettering, some of the classic 50mm lenses have got us very excited.

Sigma 50mm f/1.4 DG HSM | A review – Build and handling

When you take the Sigma 50mm f/1.4 DG HSM | A out of the box, the first thing you notice is its weight. At a hefty 815g, it comes as no surprise to learn that it is constructed from 13 elements in eight groups. This is an extremely complex arrangement for a 50mm f/1.4 lens. Most other similar optics have 6-8 elements, but Sigma clearly has a new-found confidence to manufacture this unique design, and rightly so.

In the past year or so, Sigma has reinvented itself somewhat. Gone is the rather dated cosmetic design of its lenses, replaced with a new design that looks more like a classic Zeiss lens than the 1990s-style third-party lens design that Sigma has previously been known for. And it goes beyond the purely cosmetic. As part of this new range of lenses, the company has also introduced a USB dock that allows some of the features of the lens to be updated by the user. While it obviously can’t make the optics any better, it does allow some control over the sort of settings built into the electronics, which could otherwise only be altered via a manufacturer’s firmware update.

Which features can be changed depends entirely on the lens in question. For example, on Sigma’s newest telephoto lenses, it is possible to use the USB dock and associated computer software to change the focus limit ranges of the lens. The 50mm lens doesn’t have a focus limiter, of course, but the USB dock can be used to adjust the micro-focus of the lens, just as you can in-camera. This can help to improve any slight front or back-focus issues when using the lens on a particular camera.

Believe it or not, the autofocus speed can also be improved. Sigma told us that with most lenses the speed of the autofocus motor inside a lens is actually restricted slightly. This is to aid AF acquisition by giving the system slightly more time, and to ensure that continuous focusing is smoother and less jittery, particularly when shooting video. However, if you want to get faster single AF performance, increasing the motor speed is now an option.

One feature that you will be able to add to this Sigma 50mm lens, via the USB dock, is full-time manual focus. This will allow the user to activate manual focus simply by turning the focus ring, even if the switch on the side of the lens is set to AF. In effect, it is the same as the manual-focus override found on other cameras, making it simple to tweak the focus manually without changing the AF mode. To add this feature to the Sigma 50mm f/1.4 lens, Sigma Optimization Pro Update version 1.2.0 software is needed for the USB dock. See for more details.

There are some other nice new touches. Lenses now have a numerical designation for the year in which they were manufactured. So rather than having Mark I, II or II versions of a lens, users will refer to having the 014, or 022 model. It will be a bit like referring to a fine wine, with each lens having its own particular qualities.

The design of the 014 version of this lens is similar to the 18-35mm f/1.8 zoom lens that we tested last year. It has a large ribbed rubber focus ring that is comfortable to use, even with gloves on. Beneath a small window sits the focus distance scale, while the side of the lens includes an AF/MF switch. It should be noted that this lens is not optically stabilised, which should be a consideration if you have difficulty holding heavier lenses steady. However, I used the lens with a Canon EOS-1D Mark IV and had little problem shooting handheld.

Overall, the build of the Sigma 50mm DC HSM f/1.4 lens is superb, if a little heavy, and it is amazing how a simple redesign of the body can elevate a brand to premium status, without an inflated price tag.

Sigma 50mm f/1.4 DG HSM | A review – In use

Image: As can be seen in the background of this image, the f/1.4 aperture produces lovely round specular highlights. Even though the lens isn’t at it’s sharpest at f/1.4, it can still resolve lots of detail, as can be seen in the pull-up of the hoverfly

One of the first things I noticed when using the lens is how quiet it is. The Hyper Sonic Motor (HSM) is fast and quiet, and it helps that just a quarter turn of the focus ring moves the lens from its 40cm minimum focus distance to infinity. With such a small turn required, you would think that accurate manual focusing would be difficult; however, the lens was easy to focus using the large viewfinder of the full-frame Canon EOS-1D Mark IV. I was able to focus very precisely, and while this was just as much to do with the chosen camera, the gearing of the lens and the slight firmness of the focusing ring make it possible. Once focused, the lens holds firm and doesn’t slip, requiring a quite definite turn to shift it from position.

With a 40cm minimum focus distance, the Sigma 50mm f/1.4 lens provides a magnification of 1:5.6, which is respectable for a lens of this type, just don’t expect to take too many close-up images with it.

Sigma has used its Super Multi Layer Coating in an attempt to reduce flair, and overall I found that I had no issues with it, even when taking shots of backlit blossom on trees. The coating also benefits the contrast produced by the lens, with images looking crisp, with plenty of micro-contrast between shadows and highlights, which further adds to the optic’s sharpness.

When shooting at f/1.4, the light passing through the lens is obviously unobstructed by the lens aperture. But with nine aperture blades producing an almost perfect circle, even stopping the lens down to f/2.8 and smaller produces smooth out-of-focus backgrounds. It is this shallow depth of field created by an f/1.4 aperture that makes 50mm lenses of this type so popular.

Put the Sigma 50mm f/1.4 DG HSM | A on a camera with an APS-C-sized sensor and, all of a sudden, it becomes a 75mm f/1.4 lens, which is very nice for portraiture. At f/1.4, the lens obviously isn’t at its sharpest, but for portraits this can be quite flattering, with enough sharp detail in the subject’s eyes, but with the shallow depth of field and the lens not being at its sharpest giving a slightly more flattering look to skin.

Image: Shot at f/1.4, there is plenty of detail around the subjects’s eye, and the large aperture helps to create a lovely shallow depth of field

Sigma 50mm f/1.4 DG HSM | A reveiw – Image quality

The only surprise with the Sigma 50mm f/1.4 DC HSM | A is just how good it is. Having compared its test results to those of the 50mm lenses that we tested in AP 20 July 2013, the Sigma 50mm f/1.4 lens performs better than the twelve lenses in that test, in all areas and in every respect. At its centre, it is sharper than all of the other lenses, including the older Carl Zeiss Planar T* 50mm f/1.4, which was even tested on a slightly higher-resolution Nikon D600.

As can be seen in the images here and on the test chart, the lens performs at its best at f/5.6-8, and manages to resolve quite a staggering amount of detail. Even more impressive is the performance of the lens at its edges. At f/5.6 there is not much difference between the sharpness at the sides and centre of the frame, and it is only in the very corners that the quality drops. Again, it beats nearly all other 50mm lenses in this regard, although we have not yet tested the £3,500 Carl Zeiss Otus 55mm f/1.4, something that we hope to do in an upcoming issue.

Traces of chromatic aberration were noticeable in some raw images taken with the Sigma 50mm f/1.4 GD HSM | A, but this was only visible at 100% and was removed with the merest nudge of the slider in Adobe Camera Raw.

Chart analysis

Tested on a Canon EOS-1D Mark IV
This set of graphs is one of the best that we have seen from any lens that has been through our new lens test. At f/5.6, centre resolution is better than in all of the 12-50mm lenses we tested in our round-up in AP 20 July 2013, as is vignetting. As can be seen in the shading diagram, the vignetting grid is almost flat, showing little difference between centre and edge brightness. The distortion graph shows slight pincushion distortion, whereas most 50mm lenses suffer from barrel distortion. However, it is so minimal that it should be of no concern. This lens is on a par with the best 50mm optics we have tested.

Sigma 50mm f/1.4 DG HSM | A – Our verdict

With a street price of around £850, the Sigma 50mm f/1.4 DG HSM | A isn’t cheap, with most comparable lenses costing around £500. However, the reason for the extra cost is quite clear: this lens is a unique design that breaks away from the traditional configuration of a 50mm f/1.4 lens, a bold move that pays off in image quality.

Sigma is on something of a winning streak, with the 18-35mm f/1.8 lens winning the AP Zoom Lens of the Year award last year, and already this 50mm f/1.4 lens is a strong contender for our Fixed Lens category this year. The images it produces display a staggering amount of detail across the frame, and those shooting landscapes and travel images will be impressed with its edge-to-edge sharpness.

If you are using this lens on a cropped APS-C-sensor DSLR, then it becomes a great 75mm (equivalent) portrait lens, and by using only the very centre of the image circle, the edge-to-edge sharpness becomes even greater still.

The lens looks lovely and handles just as well, but it is on its image quality that it should be judged and here I find it exceptional. If you have the money and want a 50mm f/1.4, I wouldn’t hesitate to recommend it.