In fact the 50mm f/1.4 DG HSM is one of the best lenses on the market, and possibly one of the best lenses ever built, as both the company’s early hype and our own testing reveal. This lens carries a price tag of $950 and is especially intriguing when it’s viewed in relationship to its closest competitors, the Nikon Nikkor 58mm f/1.4G and the Canon 50mm f/1.2L USM. Both of these lenses have price tags nearly double the cost of the Sigma lens, which naturally begs the question "are they twice as good as the 50mm ART?
The answer is unequivocally, "no". While the Nikon and Canon lenses have their strengths, neither is worth the $600-800 that they’ll cost over the Sigma lens, and in our tests the Sigma produces images so stunning as to quickly become our go-to portrait lens.
Sigma has put a lot of high-quality technology into this lens. It uses Super Low Distortion glass and features thirteen elements in eight groups and a "Super Multi Layer" coating that Sigma claims reduces flaring and ghosting. Sigma also uses a "floating focusing system" that the say reduces movement of the lens when focusing.
Both the Canon and and Nikon lenses focus a tad faster—that has always been my experience with Sigma lenses—most likely because the manufacturers can build a focus system that takes advantage of the key properties of their focusing motors, while Sigma has to build a lens that will work with multiple focusing systems. But as is the case with other Sigma lenses we’ve tried, that difference isn’t enough to discount the lens and this lens seems particularly speedy compared to other Sigma pro lenses.
When shooting in continual focus mode it’s possible to hear the motor moving the lens elements, a slight clicking noise as the lens adjust focus. By contrast Nikon and Canon’s lenses tend to be quieter, but this is a very subtle noise, only really noticeable if you’re listening for it.
The lens also focuses down to 15.7 inches, allowing for extreme closeup portrait work or still life photography at a nice, close distance. Canon’s 50mm f/1.2 has a minimum focus of 18-inches while 21-inches.
The tradeoff with the Sigma lens seems to come down to size and weight. The Sigma 50mm Art lens is more than an inch longer than the Nikkor 58mm and just over a pound heavier. That might not be a lot for a studio photographer with the means to put down the lens between shots but for the traveling shooter the Sigma is significantly heavier than the Nikon or Canon lenses in this class. To put this into perspective, the Nikon D750 is 750 grams without the battery installed and the Sigma 50mm is 815 grams.
But the weight of the lens aside, there are few lenses that can come close to the Sigma 50mm Art, and none at this price. DxO Labs, which makes the RAW processing software DxO Optics performs detailed lens measurements for their image processing software and they ranked the lens just below the $4000 Carl Zeiss Distagon T* Otus 1.4/55 ZE and nicely above the $1280 Carl Zeiss Makro-Planar T 50mm f/2 ZE. =
We would be hard pressed to find problems with images from the Sigma 50mm Art lens, in all of our tests the lens produced incredible images, focused fast enough for daily editorial or portrait work and lived up to the considerable hype. Subjects were tack-sharp across the aperture range, the background blur at wide aperture is beautiful yet doesn’t introduce chromatic problems. It’s a big long and a bit heavy, but that’s because there’s a lot of "awesome" to contain in a single lens.
As the lens ranks nearly as well as a lens that’s four times its price, and since it ranks better than lenses double its price, there’s very little reason to not buy the Sigma f/1.4 50mm DG HSM Art lens. It’s easily one of the most accurate and best performing lenses we’ve tested and destined to be one of history’s best pieces of glass.