Sigma AF 17-70mm f/2.8-4.5 DC (Nikon) - Review / Lab Test Report
Lens Reviews - Nikon / Nikkor (APS-C)
Article Index
Introduction
Analysis

Special thanks to Wolfgang Reinig for providing this lens for testing!

Introduction

The Sigma AF 17-70mm f/2.8-4.5 DC macro is one of many standard zooms available to Nikon users. Compared to the rest of the gang it offers a relatively long zoom range (~4x ratio) combined with a relatively large max. aperture at 17mm. Obviously it is a direct competitor to the Nikkor AF-S 18-70mm f/3.5-4.5 IF-ED DX - one of the value kings in this class. The Sigma is a DC ("Digital Camera") lens specifically designed for the reduced image circle of today's APS-C DSLRs where its field-of-view is equivalent to 26-105mm (full format) - an attractive range suitable for a variety of applications.

Unlike its in-house cousin (Sigma AF 18-50mm f/2.8) the AF 17-70mm DC is not a designated EX lens (Sigma's pro grade lineup) but the build quality is still pretty good with tight controls and no wobbling. The lens has a slight crinkle ("ZEN") finish and broad rubberized control rings. Both the zoom and focus rings operate pretty smooth. The tested sample showed a tendency for zoom creeping but Sigma has provided a zoom lock (17mm only) to manage the problem during transportation. The front element does not rotate so using a polarizer remains easily possible. As you can see in the product images below the Sigma uses a duo-cam system to extend its physical length when zooming towards the long end of the focal length range.


Note: The image above shows the Sigma AF 17-70mm f/2.8-4.5DC in Canon mount

The lens has no internal AF motor and relies on a slotted drive screw operated by the camera. As a result AF operation will generate a moderate degree of noise. The AF is moderately fast and accurate on the D200.

Specifications
Equiv. focal length25.5-105 mm (full format equivalent)
Equiv. aperturef/4.2-f/6.8 (full format equivalent, in terms of depth-of-field)
Optical construction15 elements in 12 groups inc. 1 SLD and 2 aspherical elements
Number of aperture blades7
min. focus distance0.20 m (max. magnification ratio 1:2.3)
Dimensions79 x 83 mm
Weight455 g
Filter size72 mm (non-rotating)
Hoodpetal shaped (supplied)
Other features-




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