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18-200mm
f/3.5-5.6G ED IF AF-S VR DX Zoom Nikkor
Lens Review
by Victor F. Newman
tell
a friend about this Nikkor 18-200mm lens Review
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VR
in Use
One
of the questions from anyone that has never used a VR lens before
is always “does it work?” Simply, yes. It works very well.
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This
image was made handheld at 1/2 of a second,
to show the effectiveness of the VR |
Detailed
discussions of how VR operates can be found here
and elsewhere. We’ll simplify the explanation quite a bit here.
Basically, there are very sensitive motion transducers in the
lens that detect and measure small movements (like the shake
that occurs when hand-holding the camera). The microprocessor
in the camera analyzes this movement, and sends control signals
back to the lens. Inside the lens, certain elements are moved
by tiny actuators. Operating in response to the signals from
the microprocessor, the actuators move the VR elements many
times per second. By moving the VR elements, the image projected
onto the sensor is “steadied”, so that even though the camera
is moving, the image projected onto the sensor is effectively
stationary.
This
technology has been around for several years now, and is becoming
quite mature. Nikon has chosen to call the system in this lens
“VR II” (as in second-generation) technology. This enables shots
free from motion blur while hand-holding at shutter speeds four
stops slower than dictated by the traditional “one divided by
the focal length” shutter speed guideline.
VR
is often likened to having a lens of wider aperture. While this
is true to some extent, it should be noted that VR is of little
use in freezing moving subjects. Its main use is for stationary
subject matter when shooting at slower-than-optimum shutter
speeds. This is most useful at longer focal lengths, where a
shutter speed of at least 1/300 is conventionally dictated for
sharp photos, like in the image at the top of this page.
This
lens, and the benefits of VR, would be of very little use shooting
something like available-light basketball, where a shutter speed
of 1/500 is needed to freeze motion. A typical college gym is
lit for 1/500 at f/2.8 and ISO 1600. At the wide end, the 18-200,
at f/4.5, would require a shutter speed 1.5 stops slower than
an f/2.8 lens, or 1/180 sec. Worse, at 200mm, f/5.6 would dictate
a shutter speed of 1/125 sec – completely unacceptable for moving
sports. No matter how good the VR is, it will be of no use in
a case like this. The images of the players would be blurred
due to their motion and the slow shutter speed. VR can do nothing
about that.
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On
a separate note, this comparison shows how much difference
in perspective you can achieve with this one lens. Both
shots render the foreground flowerpot at the same size
in the image, but the difference in background is dramatic.
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