TOKINA AT-X 11-20MM F/2.8 PRO DX
between autofocus and manual focus
by snapping the focus ring forward or
backward respectively. Some love it, some
hate it. Either way, you need to be careful
not to nudge the ring accidentally,
inadvertently switching between auto
and manual focusing. On balance, we
prefer the full-time manual override
facilities of the Nikon lenses.
Performance
The Tokina is impressively sharp, even when
shooting wide-open at f/2.8, at the short
end of the zoom range. During our tests,
however, sharpness was let down by
inconsistent autofocus accuracy. The
autofocus system is reasonably quick
considering it’s based on an electric motor,
but is still rather noisier than in current
competing Nikon, Sigma and Tamron
lenses. Levels of colour fringing are fairly
typical for this type of lens, but distortion
is particularly negligible at the long end of
the zoom range.
N-Photo verdict
This Tokina lens is well built and delivers nice
image quality. The f/2.8 aperture is a bonus but
autofocus accuracy proved inconsistent in our
tests. Overall, it’s a good buy at the price.Features
Build &
handling
Performance
Value4
OverallFeatures
1 With its fast f/2.8 aperture rating, the
lens has a large 82mm filter thread.2 The push-pull focus ring enables
swapping between autofocus and
manual focus.3 A focus distance scale is positioned
beneath a viewing window, but there
are no depth of field markings.4 The electric motor for driving autofocus is
relatively basic, compared with ring-type
ultrasonic and stepping motor systems.5 A rubber ring around the mounting plate
reduces the ingress of dust and moisture.6 The zoom ring placed at the rear of the
lens has a pleasantly smooth action.Barrel distortion is a little noticeable at the
short end of the zoom range but negligible
at or near the mark 20mm.Sharpness
CentreEdgeFringing
Distortion
Although the shortest zoom setting
is only a millimetre longer than in
competing Nikon lenses, the maximum
viewing angle is noticeably less wide.At its longest focal length of 20mm,
the Tokina gives the same reach as
the Nikon 10-20mm lens, but loses
out to the Nikon 10-24mm.Centre-sharpness is impressive even at f/2.8
and corner-sharpness is pretty good for a
wide-angle zoom.Amounts of lateral chromatic aberration
towards the edges and corners of the frame
are average for this type of lens.11mm, f/820mm, f/8