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Nikkor AF-S 28-70mm f/2.8 D IF-ED - Review / Test Report - Analysis |
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Lens Reviews -
Nikon / Nikkor (APS-C)
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Page 2 of 2
Distortion
The AF-S 28-70mm ED exhibits a very slight degree of barrel distortion at 28mm
decreasing to marginal distortion beyond. This is exceptional for a zoom
lens.
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Move the mouse cursor over the focal length text marks below to observe the respective distortion
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| 28mm |
40mm |
70mm |
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The chart above has a real-world size of about 120x80cm.
Vignetting
Thanks to the full frame design the Nikkor AF-S 28-70mm ED shows little
vignetting on the D200. At 28mm and 40mm the issue is already negligible at
wide-open aperture.
Interestingly the vignetting increases towards the long end of the zoom
range - probably a side effect of the camera sensor characteristic. In
very critical situations vignetting may be visible at f/2.8 here - by
f/4 the problem is gone already.
MTF (resolution)
The AF-S 28-70mm f/2.8 ED produced very good to excellent resolution figures
in the MTF lab. The center resolution is excellent throughout most of the tested
aperture range and at all focal length - it scratches and may possibly
even exceed the sensor resolution of the D200 at 28mm @ f/4.
The borders perform slightly worse than the center but catch up quite nicely when
stopping down. There's a marginal decrease in quality at 70mm which may
originate in a slight centering defect which is most obvious at this setting.
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)
Chromatic aberrations (color shadows at harsh contrast transitions) vary somewhat across
the focal length range. At 28mm the issue remains below 1px on the average at
the image borders but the issue increases towards 40mm and 70mm at large aperture settings.
Please note that lateral CAs can be easily corrected via imaging applications.
Verdict
The Nikkor AF-S 28-70mm f/2.8D IF-ED delivered a very impressive performance in the
lab. The resolution figures are very good to excellent with a highly impressive
peak performance around f/5.6. The level of distortions is exceptionally low
for a zoom lens. CAs are moderate except at 40mm @ f/2.8. Vignetting is very
well controlled. The build quality of the lens is superb and it´s a joy to handle
it despite its comparatively hefty size and weight. Typical for most classic standard
zooms it loses quite a bit of its attraction on APS-C DSLRs - a focal length
range equivalent to 42-105mm may not be up to everybody´s taste anymore.
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