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Voigtlander APO-Lanthar 180mm f/4 SL - Review / Test Report - Analysis |
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Lens Reviews -
Nikon / Nikkor (APS-C)
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Page 2 of 3
Distortions
As to be expected from a moderate tele lens the level of distortions is very low (very slight
pincushion distortions) and not field relevant.
The chart above has a real-world size of about 120x80cm.
Vignetting
On the Nikon D200 with its reduced format (APS-C) the (full format) lens exhibits only slight
vignetting at f/4 which shouldn't be problem in the field. At f/5.6 the issue is
absolutely negligible.
MTF (resolution)
The 180mm APO-Lanthar exhibited an excellent performance from f/4
up to f/8. Beyond diffraction effects are the limiting factor but it remains
easily usable till about f/16. The lens showed a very even performance across the frame.
Below is a simplified summary of the formal findings. The chart shows in line widths per picture height (LW/PH)
which can be taken as a measure for sharpness. If you want to know more about it you may check out the corresponding
Imatest Explanations.
Chromatic Aberrations (CAs)
Low lateral CAs (color shadows at harsh contrast transitions) seem to be one of the
primary design objectives of Voigtlander lenses. At less than 0.5px on the average
at the image borders the issue is not really field relevant.
Purple fringing is absolutely absent with the Voigtlander - see this sample shot at f/4.
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