| INTRODUCTION
Nikon
digital SLR cameras all use a sensor that is smaller than 35mm
film, but the cameras themselves accept standard 35mm format lenses.
The decision by Nikon to use a “cropped” sensor in its digital
cameras can be debated ad nauseum as to its merits; depending
on their subject, photographers either loved or hated the smaller
sensor format.
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The
APS-C sensor in Nikon digital SLRs has a “crop factor” of 1.5X.
Wildlife shooters immediately liked the idea of their 200mm lens
having the same angle of view as a 300mm lens. While the gains
in apparent focal length on telephoto lenses were praised by nature
shooters, the downside of this “crop factor” was that now your
17-35mm lens lost its “super-wide” ability and became a pedestrian
26-52mm lens. Many early adopters of digital flocked to their
local camera shops to purchase the large (and rather expensive)
14mm Nikkor lens. At least then they had an effective focal length
of 21mm; wide enough for some, but not truly “super wide” on a
DX format body.
Nikon
showed their commitment to digital SLR users in February 2003
when they introduced the 12-24mm
f/4.0G DX AF-S Nikkor. For the first time, here was a lens
specifically designed to cover the smaller sensor area of the
APS-C digital SLRs. Until late 2004, the Nikkor 12-24mm DX lens
was pretty much a digital shooter’s only choice for an 18-36mm
film equivalent angle of view.
However,
2005 saw new lenses introduced with super-wide focal lengths in
the Nikon F-mount from each of the three major third-party lens
manufacturers. Enter the Tokina
AT-X Pro 12-24mm f/4.0 DX, the Tamron
SP 11-18mm f/4.5-5.6 Di II, and the Sigma
10-20mm f/4.0-5.6 EX HSM. Each of these lenses are priced
substantially less than the Nikkor 12-24 DX, and appear to offer
attractive options for super-wide zooms. We at Nikonians, of course
wanted to know how the three challengers stacked up compared to
the “venerable” Nikkor.
Nikonians
was able to obtain a production-level sample of each of the four
lenses from their respective manufacturers. Before we move on,
Nikonians wants to thank Nikon
USA, Tamron
USA, Sigma
Corporation of America, and THK
Photo Products for loaning us these lenses for our tests.
We also appreciate Roberts
Distributors, who went out of their way and arranged for us
to get the lenses on very short notice.
THE
SIGMA 12-24mm LENS
Some
may ask why the Sigma
12-24mm was not included in this test. All reports are that
the Sigma is a very fine lens, and it has the virtue of working
on 35mm bodies at all focal lengths. If that’s important to you,
the Sigma 12-24mm is the clear choice. If you’re looking for a
DX format super-wide lens that will let you easily use filters
(the primary drawback of the Sigma), one of the four in this review
is currently the only choice.
THE TESTS
So,
with a camera bag full of super-wides, a Nikon
D2x and a Nikon
D70, the three of us set out to put these lenses through their
paces. We tested these lenses in real-world conditions; anyone
who wants to dwell on MTF charts can look them up from the manufacturer’s
own websites. We approached this review from the perspective of
the Nikonian who is looking to get back their wide angle of view
that they were used to with an 18-35mm or 17-35mm lens on their
film body. Chances are, if you want a lens this wide, you’re either
shooting landscapes or photojournalism-style photography.
To
level the playing field between cameras, we shot our test images
in JPEG mode with sharpening set to medium-high in the camera.
Both cameras were tripod mounted and set to ISO 200, and we used
aperture-priority matrix metering. We also shot some images in
RAW to evaluate post-processing techniques for removing vignetting
and chromatic aberration. We looked at sample images at 12mm,
18mm, and (where available) 24mm. For the Sigma 10-20mm, we also
looked at images made at 20mm and 10mm.
We
shot a series of images with each lens at a range of f-stops;
from wide-open to f/22. We repeated the image series at each focal
length for each lens. The test shots were then subjectively evaluated
for center and edge sharpness, chromatic aberration, and light
fall-off (vignetting). We also judged the build and handling characteristics
of each lens.
So
here, alphabetically, are our individual reviews of each of these
super-wide lenses, followed by our summary and conclusions..
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