The Sigma 50mm f/1.4 EX DG HSM is built similar to current Nikon prime lenses – it has a solid plastic exterior and a metal mount. The lens feels very solid in hands and its large size and heavy weight make it feel like handling the Nikon 24mm f/1.4G. It is almost twice heavier than the Nikon 50mm f/1.8G, which is only 280 grams, and almost three times heavier than the Nikon 50mm f/1.8G (185 grams). The 77mm filter thread is a little too big for a 50mm lens in my opinion, because 77mm filters are expensive. Those who use 77mm filters like polarizing filter will probably be happy about not having to use a step-up ring, but such filters typically get rarely used on 50mm lenses in first place. There is, however, an advantage to having such large front element – as you will see in image samples below, it helps in reducing vignetting at large apertures. Here is how the Sigma compares to other Nikkor lenses (From left to right: Nikon 50mm f/1.8D, Nikon 50mm f/1.8G, Nikon 50mm f/1.4D, Nikon 50mm f/1.4G and Sigma 50mm f/1.4 EX DG HSM): NIKON D3S + 24-70mm f/2.8 @ 70mm, ISO 400, 1/80, f/5.6 With a large 1.4 aperture, the Sigma 50mm 1.4 prime lens is a pro level performer for shooting everything including portrait photography, landscape photography, studio photography and street photography. The Sigma 50mm f/1.4 DG has fantastic optics — but its mechanics and potential for future camera incompatibility are why you pay less for Sigma than for a professional Nikon or Canon lens.

The wide maximum F1.4 aperture means this lens works amazingly will in lowlight conditions like photographing gigs or capturing those unforgettable moments at a wedding reception. But it can also create the most attractive shallow depth of field and blue to your images. This is a quality that a lot of photographers strive to achieve, and with this lens, it's easy. Hyper Sonic Motor (HSM) System Utilizing know-how and the latest design technology accumulated through the past developments, it corrects the aberration thoroughly and achieves high resolution and astonishing rendering performance even near the edge of the image. When used on a DX or APS-C camera, it sees an angle of view similar to what an 80mm lens sees when used on an FX or 35mm camera. Under exacting test conditions, this Sigma lens is sharper than Nikon's and Canon's best, and sharper than LEICA's 50mm f/1.4 ASPH. This Sigma lens also has no distortion, unlike any f/1.4 or f/1.2 lens from LEICA, Canon or Nikon.Chromatic aberration is the lens' inability to focus on the sensor or film all colours of visible light at the same point. Severe chromatic aberration gives a noticeable fringing or a halo effect around sharp edges within the picture. It can be cured in software. For this review, we will test the Canon EF-mount version of this lens on a Canon 5D Mark IV full frame body. Who Is the Sigma 50mm f/1.4 DG HSM Art For? The Sigma 50mm f/1.4 DG has no visible distortion, which is much better than any f/1.4 or f/1.2 lens I've ever tested. The Sigma 50mm f/1.4 DG HSM Art lens delivers what it promises. It’s great quality for the price. But it is not cheap. Still, if you’re looking for the best-value lens, this is better than similar top-of-the-line lenses. (Ones from original camera manufacturers.)

For axial chromatic aberration that is hard to correct even during the image processing, SLD (Special Low Dispersion) glass elements are incorporated, ensuring high image quality throughout the entire focusing range. The lens achieves sharp and high contrast image rendering. It is supposed to work on all EOS cameras, which means everything from 1987's EOS 650 to everything in 2014. As an off-brand lens it has unproven (with me) service facilities, and unknown future parts availability. When the HSM motor dies, you're dead unless you can get a replacement part — and you just might not be able to in 10 years when you'd most need it.The price of this lens puts it in its own category. The Canon and Nikon equivalents are set at the lower end in the 50mm f/1.4 category. Meanwhile, the Sony-Zeiss lens and Canon’s EF 50mm f/1.2L lens are among the most expensive prime alternatives. Lateral chromatic aberration is even better controlled in the DN lens compared with its forebear, which was already very good. As such, there’s virtually no color fringing to be seen towards the edges and corners of the frame. Axial chromatic aberration is also minimal, so there’s very little fringing around high-contrast edges in scenes that fall just in front of or behind the plane of focus. Resistance to ghosting and flare is again impressive. Bokeh is lusciously soft and dreamy. We noticed some ‘onion ring’ effect with the DG lens in defocused lights and bright spots but this is much more minimal in the DN lens.

The lens already starts strong at f/1.4, with impressive center and mid-frame performance. Corners are a bit weak, but that’s expected from a fast prime lens. Stopping down the lens improves sharpness significantly, with amazing sharpness levels reached in the f/4-f/5.6 range. The Sigma 50mm f/1.4 Art is one of the few lenses that could reach such high sharpness levels, making it one of the best performing prime lenses we have tested so far. If you want to see how impressive this lens is to other 50mm primes, take a look at the Lens Comparisons section of the review. Please note that the above images were shot without filters. Using UV and other filters can potentially introduce more flares and ghosting to your images. Canon EOS 6D + 50mm @ 50mm, ISO 100, 1/500, f/5.6 Distortion 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 nice thing about this lens is that it’s eligible for Sigma’s mount-conversion service. If you buy this lens and then switch camera systems in the future, they can change the mount for you.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. Apochromatic lenses have special lens elements (aspheric, extra-low dispersion etc) to minimize the problem, hence they usually cost more.

I've greatly exaggerated what little there is by shooting a gray field and presented the images against another gray field: What does the Sigma 50mm f/1.4 offer to the already saturated market of excellent 50mm lenses from every DSLR manufacturer? For many years the focal length of 50mm lenses was considered a “standard” or “normal” focal length, because it closely resembles the perspective of the human eye. These lenses were widely popular on film cameras and the focal length was ideal for portraiture and everyday photography. As digital SLRs and zoom lenses started taking over the market, the popularity of 50mm primes also decreased. The smaller size of APS-C sensors made the field of view of 50mm lenses narrower, while the flexibility of zoom lenses and their low price drove the demand towards convenience. Now that full-frame digital cameras are getting more and more affordable, the once-forgotten 50mm lenses are regaining their popularity among many photographers. Seeing this trend, some manufacturers including Nikon have been updating and renewing their 50mm lens lines. Sigma, being a third party lens manufacturer for many brands, introduced their flagship Sigma 50mm f/1.4 EX DG HSM in 2008 and has been marketing it as a higher-quality f/1.4 lens with better characteristics than most branded 50mm f/1.4 lenses. New cameras may or may not work with this lens, and off-brand lens makers only sometimes will update lenses to work on new model cameras. Ten or more years from now I know my Nikon and Canon lenses will work on new cameras, but I don't have any high hopes for any off-brand lens. The Sigma 50mm f/1.4 is astoundingly sharp at every setting. You just need to be sure it's in focus and that nothing moves. As you can see, the detail level at f/1.4 is very high. I shot many images between f/1.4 and f/2.8 in this review, specifically to demonstrate the sharpness capabilities of this lens. Canon EOS 6D + 50mm @ 50mm, ISO 100, 1/1000, f/1.6 BokehAmateurs waste too much time worrying about lens sharpness, and since this lens is designed for amateurs, it's super sharp. It has threads to accept 77mm filters. This 77mm thread does not rotate after focusing (similarly to the Canon L variant). This is ideal for those who like ND and CPL filters on their lens. 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.