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Sigma AF 17-70mm f/2.8-4.5 DC (Nikon) - Review / Lab Test Report |
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Lens Reviews -
Nikon / Nikkor (APS-C)
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Page 1 of 2
Review by Klaus Schroiff, published May 2007
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 |
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| Equiv. focal length | 25.5-105 mm (full format equivalent) |
| Equiv. aperture | f/4.2-f/6.8 (full format equivalent, in terms of depth-of-field) |
| Optical construction | 15 elements in 12 groups inc. 1 SLD and 2 aspherical elements |
| Number of aperture blades | 7 |
| min. focus distance | 0.20 m (max. magnification ratio 1:2.3) |
| Dimensions | 79 x 83 mm |
| Weight | 455 g |
| Filter size | 72 mm (non-rotating) |
| Hood | petal shaped (supplied) |
| Other features | - |
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