Admitedly, the Sigma is slightly slower
than its competition but is lighter by
410g and uses a smaller diameter
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compared to the Canon and Nikon
above. The Sigma does not offer a
tripod collar.
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elements in 15 groups, with 4x
SLD glass elements to minimise
chromatic aberrations and includes
an electromagnetic diaphragm
mechanism. Super Multi-Layer
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ghosting and thus offer better contrast.
The front element has a special coat
applied to it to repel oil and water. The
autofocus system incorporates a Hyper
Sonic Motor (HSM) for fast and silent
focussing. Full-time manual focussing
is possible. To optimise sharpness
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when shooting hand-held, the lens
offers an optical stabiliser (OS). Sigma,
Unfortunately, does not mention how
many stops advantage the OS gives
this lens. Even though the Sigma is
not a macro lens, it offers a maximum
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quite good. The lens mount is made of
metal and offers a rubber seal to prevent
dust or water from entering the lens.A white raised dot at the rear end helps
to align the lens to the camera body.
A Zoom Lock prevents zoom creep
by locking the ring at 100mm setting.
Four other switches control the lens
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time MF) and MF]; Focus Limiter (Full,
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Custom Mode Switch. The Custom Mode
Switch, in conjunction with the optionalUSB Dock and its dedicated software
(Sigma Optimization Pro) allows you
to customise and save the AF speed,
Optical Stabiliser effect and the range
of Focus Limiter of the lens.Note: For regular use, the Custom
Mode Switch is set to Off. The Focus
Limiter switch does not function when
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available from Sigma. These converters
can increase the focal length from
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only). Tele-converters from other
manufacturers cannot be used with
this lens. Sigma’s optional USB Dock
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available.http://www.smartphotography.in 121
Smart PhotographyJuly 2017