| THE
TOKINA
AT-X 124 AF Pro DX 12-24mm f/4.0 "Super Wide Angle"
Zoom Lens
Let's
take a look at the Tokina option. With a street price of $480
US, this lens has attracted much interest from amateurs as a direct
competitor to the 12-24mm
DX Nikkor.
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12-24mm f/4.0 AT-X Pro AF Tokina Super Wide Angle Zoom Lens
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BUILD
/ PHYSICAL CHARACTERISTICS
The
Tokina 12-24mm lens is hefty, weighing in at over one pound (570g),
making it the heaviest lens we tested. It has a black crackle-coat
finish reminiscent of the early AF-I Nikkor lenses. The zoom ring
is close to the rear of this lens, and the focus ring is towards
the front. The two rings have different widths and textures so
they can easily be distinguished. This lens is a G design, with
no aperture ring.
This
lens takes 77mm front filters, and has a pinch-front style lens
cap that can easily be attached or removed with the bayonet-mount
lens hood installed. The focus mechanism is internal, and the
distance scale reads from 1-7 feet and infinity. There are no
hyperfocal markings on this lens. The large, petal-shaped lens
hood is reversible and has a black velvet lining.
The
Tokina 12-24mm uses a standard AF drive, but MF override is possible
by sliding the focusing ring towards the rear of the lens. This
feature enables MF override without switching the focus mode selector
on the body of your camera. Internally, the lens features an optical
formula of 13 elements in 11 groups and a nine-bladed aperture.
The
lens has a constant maximum aperture of f/4.0 throughout the zoom
range, and a close-focusing distance of just under one foot. Because
this lens has a DX design, the image circle is too small to
cover the frame on a 35mm body. However, our testing suggests
that you could use this lens on a film body between 19-24mm and
get minimal vignetting.
PERFORMANCE
With
both bodies, autofocus with the Tokina 12-24mm is crisp and precise.
Expect better low-light focusing performance with the CAM2000
module of the D2x. However, with a lens this wide, autofocus seems
hardly necessary. The lens has a nice feel in the hand, and its
weight makes it feel like a pro lens. Images with this lens
have good contrast at all apertures and focal lengths. Center
sharpness is good at 12mm, and very good to excellent at the longer
focal lengths or when stopped down to f/8 or f/11. The edges of
images taken at 12mm and wide-open are noticeably softer than
the center when viewed at 100% in Photoshop. There is moderate
light fall-off with this lens, especially at 12mm, which goes
away by f/8. Above f/16, there is noticeable softening of images
due to diffraction effects. At 18mm and 24mm, this lens yields
good to very good sharpness in the edges, especially when stopped
down. In our test sample, we noticed that images at f/11 and f/16
were noticeably dark compared to those taken with other wide lenses,
but this was a uniform effect that could easily be adjusted with
post-processing, and did not appear to be a metering issue. This
effect may be due to sample variation, but we have no way of testing
this hypothesis without additional copies of the lens.
Optical
distortion is controlled very nicely in this lens. There is slight
pincushion distortion at 12mm, and very little, if any, barrel
distortion at 24mm. At the wide end, chromatic aberration (CA)
was apparent in images taken with the D2x, but it was very minor;
about one pixel in width at 100%. Nit-pickers will be able to
remove the CA effects easily enough with Photoshop CS2 or in RAW
files with Nikon Capture software.
When used with a standard polarizing filter, we observed vignetting
at 12mm with the Tokina 12-24mm lens. This vignetting was gone
by 14mm or so.
CONCLUSIONS
The
Tokina AT-X 12-24mm lens is a fine performer, especially at focal
lengths longer than 12mm. At 12mm, performance is good, but plan
on shooting at f/8 or higher for maximum sharpness in the edges
of the frame. For landscape work, this is practically a non-issue.
The constant aperture design and nine-bladed diaphragm are nice
touches on this lens.
This
lens is a good choice for Nikon shooters who:
Cannot afford the Nikkor 12-24mm DX lens
Shoot stopped-down most of the time, such as landscapes
Dont need AF-S focusing, but want a fast maximum aperture
Have a 28-70mm mid-range zoom, and need 24mm focal length
in their kit
On
the other hand, this lens may not be for you if:
You are a sharpness freak and do a lot of shooting at 18-24mm.
You need AF-S focusing
You are shooting wide-open most of the time
You want a lightweight lens
Our
opinion is that this lens is a worthy alternative to the Nikkor
12-24mm DX if price is an issue and you need a super-wide zoom.
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