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 The lens has a certain plastic feeling. But overall, it’s a durable lens. The handling of this glass is pretty good. The rubber elements, like the focusing ring and the grip, provide a steady hold. Generally speaking, the Sigma 50mm f/1.4 DG HSM brings reasonable resolving power. So it won’t break even under the pressure of a high-megapixel sensor. Sunstar, partly shielded sun, 02 September 2014. ( Nikon D810, Sigma 50mm f/1.4, f/8 at 1/250 at Auto ISO 100, Athentech Perfectly Clear.) bigger. 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.

This Sigma lens is much bigger, heavier and more expensive than similar camera-brand lenses like the superb Nikon 50mm f/1.4 G.

The HSM (Hyper Sonic Motor) ensures a silent, high-speed AF function. Optimizing AF algorithm, smoother AF is achieved. Also, this lens can offer full-time MF function by rotating the focus ring of the lens while auto focusing. Without changing the AF/MF Focus Mode Switch, it allows faster focus adjustment. 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.

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. I compared my Sigma directly to my Nikon 50/1.4G and my Micro-NIKKOR 55mm f/2.8 AF on the test range at infinity. The staple Sigma 50mm 1.4 DG HSM has been redesigned and reengineered to set a new standard for the Art line. 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. A Hyper Sonic Motor (HSM) ensures quiet, smooth and accurate autofocusing and paired with Special Low Dispersion (SLD) glass and Super Multi-Layer coating, the 50mm 1.4 is a high performance lens for the modern DSLR sensors. 13 elements in 8 groups allow for unsurpassed performance even at wide apertures and close-up photography is easily managed with a minimum focusing distance of 40cm. The Sigma 50mm 1.4 lens is the new exceptional standard, standard prime.It tips the scales at 1.8 lb (815 g). And it measures 3.9 inches (99.9 mm) in length. So the casual hobbyist might find it a bit too much lens to carry around. There are no visible sharpness differences between this Sigma and other 50mm lenses at normal shooting apertures. At f/4 and smaller, all these 50mm lenses are the same, and even the f/1.8 lenses are indistinguishable from one another. It is ideal for a wide aperture standard lens to have a high rendering performance from open aperture throughout the entire image. For instance, the molded glass aspherical lens elements provide excellent correction to sagittal coma flare. It is perfect for astronomical photography and shooting of illumination because of the reduced blur on the point light sources near the edge of the image. It also creates an attractive bokeh in portraits and indoor shooting. According to DxoMark metrics, it resolves 40 P-Mpix on a 50.6 MP (megapixel) Canon 5DS R model. This is an impressive sharpness score.

When it comes to handling high-contrast situations with a bright source behind the subject, the Sigma 50mm f/1.4 Art seems to yield quite pleasing results, keeping the contrast levels high and introducing very little ghosting and flare into images. Here is a sample image taken with the sun on the top right corner of the frame: Canon EOS 6D + 50mm @ 50mm, ISO 100, 1/640, f/1.6 This Sigma has no measurable distortion at distances of 1 meter or more. It has slight barrel distortion at its closest focus distance.Amateurs waste too much time worrying about lens sharpness, and since this lens is designed for amateurs, it's super sharp. The distortion at the closest distance isn't visible and can be corrected easily by plugging these figures into Photoshop's I may be a little weird, but I always invest long term. I'd be shy about this Sigma lens because I demand the lens I buy today to be earning money for me for at least the next 20 years, and to still be serviceable and valuable when I sell the lens after all that time. My Nikon and Canon pro lenses do this for me. I bought my Nikon 17-35mm f/2.8 AF-S in the 1990s, and it's still Nikon's top professional ultrawide zoom 15 years later (the Nikon 16-35 VR is only a consumer lens, and the Nikon 14-24 is a special-purpose lens much less useful than the 17-35). My 17-35/2.8 is still worth, used, what I paid for it new. A deep petal-shaped hood is supplied with this lens, which does a good job of shielding the lens from extraneous light that may cause loss of contrast or flare. Even when shooting into the light, contrast remains good and flare is virtually non-existent.