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Nikkor AF 28-70mm f/3.5-4.5D - 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 28-70mm has a very moderate zoom ratio of just 2.5x so you would normally
expect little distortion. At 28mm there's a quite pronounced degree of barrel
distortion (2%) which decreases towards the long end of the zoom range. At 70mm
the results are basically free of distortion. A quite good characteristic for a zoom.
24mm:
40mm:
70mm:
The chart above has a real-world size of about 120x80cm.
Vignetting
The AF 28-70mm is a full frame lens so on an APS-C DSLR it can take
advantage of a sweet spot effect and the issue is very well
controlled indeed. Even at wide-open aperture there's very little
vignetting (around 0.5EV) and naturally even less so when stopped
down a little.
MTF (resolution)
The Nikkor AF 28-70mm f/3.5-4.5D may be an old lens but it produced
very impressive resolution figures in the lab. Wide-open the center
performance is already very good throughout the range and at medium
apertures the quality is even excellent. Surprisingly the
borders can follow closely except at 28mm but even here the difference
isn't overly pronounced. There are slight RSAs (Residual spherical
aberrations = focus shifts when stopping down) at the wide-end of
the zoom range.
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)
The Nikkor produces a moderate degree of chromatic aberrations (color shadows at
harsh contrast transitions) throughout the zoom range peaking in an average
width of around 1px at the image borders.
Verdict
The Nikkor AF 28-70mm f/3.5-4.5D is an old lens but surprisingly it performed
really good on the Nikon D200. The resolution figures are on a very high level
and pretty even across the APS-C image frame. Vignetting is pretty low and
the level of CAs is quite moderate.Typical for most standard zooms there's
pronounced degree of barrel distortions at 28mm but otherwise it is a minor issue.
The build quality is Ok but some may not like the rotating front element. Unfortunately
the zoom range (equivalent to 42-105mm) isn't really all that attractive on an
APS-C DSLR anymore.
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