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Nikkor AF-S 300mm f/4D IF-ED - Review / Test Report - Analysis |
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Lens Reviews -
Nikon / Nikkor (APS-C)
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Page 2 of 3
Distortion
The naked AF 300mm f/4D IF-ED produces an insignificant degree of distortion only
measurable under lab conditions. Adding tele-converters does merely affect this
base characteristic.
The chart above has a real-world size of about 120x80cm.
Vignetting
The AF-S 300mm f/4 is a full frame lens so it can take advantage of a sweet spot
behavior on the D200. Vignetting is detectable at f/4 (0.4EV) but it shouldn't
be overly field-relevant. At f/5.6 vignetting is absolutely negligible.
There's even less vignetting at wide-open aperture when adding a Nikkor AF-S 1.4x
or a third-party (Soligor) AF 1.7x DG converter.
MTF (resolution)
The AF-S 300mm f/4D IF-ED produced very-good to excellent resolution figures
under lab conditions. The performance at f/4 is already great in the center of
the image. The borders follow on a very good level at this setting.
The peak performance is reached at f/8 with an increase in quality primarily
at the borders.
Adding a tele-converter always comes at cost of a performance penalty but
with the Nikkor AF-S 1.4x the decrease in quality remains relatively moderate.
Nonetheless the resolution figure are only good (borders) to very-good (center)
at f/4. Stopping down helps to lift the quality especially at the borders.
The Soligor AF 1.7x DG is a third-party converter (probably a Kenko clone)
which pushes the limits a little more (~510mm f/6.7). However, at wide-open
aperture the resulting border quality is quite poor. At f/9.5 (f/8 is displayed
in the viewfinder) the quality is pretty decent though.
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)
CAs (color shadows at harsh contrast transitions) are pretty well controlled with
an average CA pixel width of less than 1px at the borders. The converters magnify
CAs but the situation remains pretty acceptable. Purple fringing doesn't seem
to be an issue with this lens.
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