Nikkor AF 70-210mm f/4 - Review / Lab Test Report - Analysis |
Lens Reviews -
Nikon / Nikkor (APS-C)
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Page 2 of 2
Distortion
The Nikkor AF 70-210mm f/4 shows an unusually low level of distortion for a zoom lens.
At 70mm there is slight barrel distortion changing to slight pincushion distortion
towards the long end of the zoom range.
Move the mouse cursor over the focal length text marks below to observe the respective distortion
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70mm |
135mm |
210mm |
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The chart above has a real-world size of about 120x80cm.
Vignetting
As mentioned the Nikkor is a full format lens which can take advantage of a sweet
spot effect on the D200. The vignetting is indeed very low at 70mm and 135mm but
somewhat more pronounced at 210mm (0.8EV). In critical scenes you may prefer
to stop down a little at this setting.
MTF (resolution)
The Nikkor AF 70-210mm f/4 was able to deliver good resolution figures in the lab.
At 70mm the quality is even excellent and about on par with fix-focal length lenses.
However, at wide-open aperture the border resolution drops substantially at 135mm and 200mm
accompanied by reduced contrast so it is advisable to stop down a little to overcome
this weakness.
Please note that the MTF results are not directly comparable across the different systems!
Below is a simplified summary of the formal findings. The chart shows line widths per picture height (LW/PH) which can be taken as a measure for sharpness.
If you want to know more about the MTF50 figures you may check out the corresponding Imatest Explanations
Chromatic Aberrations (CAs)
Lateral Chromatic aberrations (color shadows at harsh contrast transitions) are
quite well controlled with an average width of around 1px at the image borders.
Unfortunately the lens suffers from purple fringing in extreme situations which
cannot be corrected as easily as lateral CAs.
Verdict
The Nikkor AF 70-210mm f/4 delivered decent but not exceptional results.
The resolution is excellent at 70mm but a little soft at 135mm @ f/4 and
210mm @ f/4 so the speed advantage compared to current consumer grade zoom
lenses is somewhat relativized - stopping down to f/5.6 is advisable here.
Despite the full format design vignetting is a little high at 210mm at
wide-open aperture but otherwise it is well controlled. The level of distortions
is unusually low for a zoom lens. Lateral CAs are moderate but purple fringing
can be a problem in harsh contrast situations. The build quality is relatively
decent although the approach is a bit dated.
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