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Sigma AF 18-200mm f/3.5-6.3 DC OS (Canon) - Review / Test Report |
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Lens Reviews -
Canon EOS (APS-C)
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Page 1 of 3
Review by Klaus Schroiff, published August 2007
Introduction
At the time Nikon released the AF-S 18-200mm f/3.5-5.6 VR they did not only generate
a hype in the Nikon community - they also produced an itch among Canon users. Canon
may offer lots of IS lenses but so far they were not willing to offer a cure
for the desire for a long range IS consumer-grade zoom lens. It's not that they can't
do it - Canon released the full-format EF 28-300mm f/3.5-5.6 USM L IS a couple of
years prior of the Nikon - but for whatever reason they seem to reluctant to provide
a solution dedicated to APS-C DSLRs. Anyway, Sigma is obviously more than happy to fill
this gap with the new Sigma AF 18-200mm f/3.5-6.3 DC OS. It is their 2nd zoom lens with
an OS (Optical Stabilizer) and also their 2nd APS-C standard zoom lens with a 11x zoom ratio.
In classic terms it offers a field-of-view equivalent to about 29-320mm (1.6x crop).
The build quality of the Sigma is surprisingly good. Unlike e.g. the Tamron 18-250mm
it is a comparatively big and massive lens - probably also a side effect of the
quality materials. In absolute terms it is naturally still small package when taking the
extreme zoom range into account. The lens shows no significant wobbling despite the
duo-cam design - the two inner lens tubes extend when zooming towards the long end of
the zoom range. The broad, rubberized zoom ring operates a bit stiff whereas the focus
ring feels pretty smooth. The tested sample did not suffer from zoom creeping (which may
develop over time) but Sigma implemented a transport lock (18mm only) just in case.
The front element does not rotate so using an polarizer remains easily possible.
The Sigma uses a conventional AF micro-motor which works quite fast and reasonably
accurate. I'm glad to report that the OS (Optical Stabilizer) works as advertised - it
can give you an extra potential equivalent to about 3 f-stops. There's only a single
mode OS-switch (on/off) but the lens is able to detect panning (object tracking) which
is different compared to Canon's IS implementation.
| Specifications |
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| Equiv. focal length | 29-320 mm (full format equivalent) |
| Equiv. aperture | f/5.6-f/10 (full format equivalent, in terms of depth-of-field) |
| Optical construction | 18 elements in 13 groups inc. 1x SLD and 3x aspherical elements |
| Number of aperture blades | 7 |
| min. focus distance | 0.45 m (max. magnification ratio ~1:3.9) |
| Dimensions | 79x100 mm |
| Weight | 610 g |
| Filter size | 72 mm (non-rotating) |
| Hood | supplied, petal-shaped, snap-on type |
| Other features | OS (Optical Stabilizer) |
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