Sigma 18-35mm f/1.8 DC HSM Art Review
A part of Sigma’s Art series, the Sigma 18-35mm f/1.8 DC HSM is a wide-angle to standard zoom lens that is meant for cameras that have the APS-C sensor. In fact, it is the first zoom lens that features a constant f/1.8 aperture. This not only allows shooters to take shots in darker conditions but also allows for a much shallower depth of filed compared to other lenses out there. This is what makes it notable among its competitors.
On a camera that has a 1.5x crop factor, the Sigma 18-35mm f/1.8 DC HSM offers an approximate field of view range 27-52.5mm on a 35mm camera. Thus, it makes for a useful range of wide-angle to normal focal lengths. Also, unlike many zoom lenses, the aperture of this lens stays constant through the zoom range, the maximum being f/1.8 and minimum being f/16. Although the lens does not feature image stabilization features, the wide aperture compensates for its absence by offering shutter speeds twice as fast in low light. The lens features separate zoom and focusing rings, with the focal lengths being marked.
As such, the Sigma 18-35mm f/1.8 DC HSM ships with the front and rear caps, lens hood, and the soft case.
Sharpness
The Sigma 18-35mm f/1.8 DC HSM is an extremely sharp lens. Even at f/1.8, it is wide open, which isn’t very typical. The Sigma brings out little corner softness, which a problem with most wide-aperture lenses, and sharpness in the middle of the frame. Considering this, the lens beats many prime lenses in its range of focal length.
The sweet spot is surely between f/2 and f/2.8 for center sharpness. The overall frame is the sharpest at f/2.8.
Chromatic aberration
The lens does well in keeping chromatic aberration to a low. The wide-angle focal lengths show more chromatic aberration and it gradually decreases at 35mm. At 18mm, you will see more chromatic aberration at the corners but that stoops down for longer focal lengths and balances out.
Shading/Vignetting
Vignetting is very well controlled in the Sigma 18-35mm f/1.8 DC HSM. There is some vignetting with apertures more than f/4 but it isn’t all too high and pretty constant at best. At f/4 and beyond, vignetting is hardly noticeable.
Distortion
Distortion on the Sigma 18-35mm f/1.8 DC HSM is pretty controlled but not completely eliminated. At focal lengths wider than 24mm, we see some amount of barrel distortion. This is still lesser than we usually expect from a zoom. At 24mm, the average distortion is almost zero percent but pincushion distortion at the corners appear. As the focal length increases from 24 to 35mm, there is a very feeble increase in barrel distortion and pincushion.
Autofocus
The lens is pretty quick with autofocus and it takes one second at most from the closest object to infinity. This is owed to its Hyper Sonic Motor. It locks on to targets easily and quickly and it does very well.
Small changes in focus also happen fast and the AF motor is very much silent.
Conclusion
The Sigma 18-35mm f/1.8 DC HSM Art is one that has a bunch of real quality features and offers great image quality. Images come out sharp at all apertures and there is good control over distortion, CA, and shading. Furthermore, a great build quality adds to the offing.
Sigma Lens Singapore has both Canon and Nikon mount for this model and its available in our camera shop.
The Sigma 18-35mm f/1.8 DC HSM Art Review by DG Electronics