Sigma AF 17-70mm f/2.8-4 DC HSM OS | C (Nikon) - Review / Test Report
Lens Reviews - Nikon / Nikkor (APS-C)

Review by Markus Stamm, published July 2013

Introduction

Sigma's new "Global Vision" divides their lens portfolio into three main categories: "Art", "Sports" and "Contemporary". Over the coming years, the latter category will probably gather the most products, but at least at the time of this review there is only one lens carrying the "contemporary" tag: the AF 17-70mm f/2.8-4 DC Macro OS HSM | C.

On first sight, one might think this is simpy an old lens with a new label, since a lens with almost exactly the same name existed already. However, the new contemporary lens features an upgraded if not completely new design with less elements in total, but now including 2 FLD and one SLD element. In addition, it's a bit smaller and lighter than its predecessor.

So, let's have a look at how the lens performs on our current DX test camera, the Nikon D7000.

The lens features the new clean and modern barrel design. Apart from that, not much has changed, which includes both good and less exciting properties of the predecessor.

The lens is tightly assembled with good and solid build quality. It features a duo-cam system that extends when zooming towards the tele setting. There is only a very marginal amount of wobbling in the zoom mechanism even at the most extreme zoom setting. The front element does not rotate, so using a polarizer remains easily possible.

The two control rings have a smooth, pleasant action. Both rings rotate in "Canon" style, which is the exact opposite of how these rings work on Nikkor lenses. So, anyone used to the Nikon way of zooming may occasionally find himself zooming in the wrong direction.

It's a little disappointing that the focus ring still rotates during autofocus operations. In addition, the lens still features a simplified version of Sigma's HSM (hypersonic AF motor), which is fast and nearly silent, but does not allow full-time manual (FTM) override in single-shot AF mode. To focus manually, the lens needs to be set to the corresponding mode with the usual A/M switch on the lens barrel.

The good new is, however, that thanks to HSM the lens is fully compatible with all Nikon DX DSLRs, including the entry-level models.

It is worth mentioning that the lens carries a "macro" in its name. You shouldn't expect the performance levels of a true macro lens here but the Sigma can focus down to 0.22m which translates to a max. object magnification of 1:2.9 at 70mm. This is slightly less magnification than its predecessor, but still good enough for some basic close-focus applications.

The lens features Sigma's OS ("Optical Stabilizer"). As already reported in previous reviews it is impressively efficient and as good as the Nikon implementation. Sigma claims a gain of 4-stops which doesn't seem to be unrealistic. Actual results will vary depending on the photographer, of course.

The Sigma is a G-type lens and does not have a dedicated aperture ring.

Specifications
Equiv. focal length25.5-105 mm (full format equivalent)
Equiv. aperturef/4.2-f/6 (full format equivalent, in terms of depth-of-field)
Optical construction16 elements in 14 groups inc. 2 FLD and 1 SLD elements
Number of aperture blades7 (rounded)
min. focus distance0.22 m (max. magnification ratio 1:2.9)
Dimensions79 x 82 mm
Weight470 g
Filter size72 mm (non-rotating)
Hoodpetal-shaped, bayonet mount (supplied)
Other featuresOptical stabilization (OS), Hypersonic AF drive (HSM)




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