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Nikkor AF 28mm f/2.8D - 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 28mm f/2.8D exhibits relatively pronounced barrel distortion (1.2%) which
is a little more than desirable for a fix-focal lens.
The chart above has a real-world size of about 120x80cm.
Vignetting
The AF 28mm f/2.8D is a full frame lens thus enjoying a sweet spot advantage
on APS-C DSLRs. Nonetheless it still produces very pronounced vignetting of
one full stop at wide-open aperture (f/2.8) - a little disappointing.
However, from f/4 and up the issue is not field-relevant anymore.
MTF (resolution)
The Nikkor produced very decent resolution figures in the MTF lab.
The center performance is already very high at wide-open aperture and it even
reaches the resolution limits of the D200 by f/5.6. The border quality is
very good but doesn't really improve when stopping down (as opposed to the
depth-of-field naturally).
Similar to the Nikkor AF 24mm f/2.8 D the lens suffers from residual spherical
aberrations (focus shifts when stopping down) - a fate shared by a couple of lenses
of that design era. The lens also exhibits a quite high degree of field curvature.
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) are relatively
low at wide-open aperture but they increase when stopping down. At f/8 CAs peak
at around 1.6 pixels on the average at the image borders - this is too high for
a fix-focal lens. Please note that the issue can be corrected via several imaging
applications or tools.
Verdict
The principal design of the Nikkor AF 28mm f/2.8D is obviously closely related to
the AF 24mm f/2.8D so it shares some of its characteristics. The resolution figures
are very good but otherwise the lens left something to be desired for a fix-focal.
The lens exhibits relatively high barrel distortions, very high vignetting
at f/2.8 and pronounced CAs. Spherical aberrations (focus shifts when stopping
down) and high field curvature on top don't make things any better. Compared to
modern lenses the Nikkor seems to be a little dated but naturally it still remains
a very good lens with a few bugs.
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