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Hartblei Super-Rotator 80mm f/2.8 MC - Review / Test Report - Analysis |
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Lens Reviews -
Canon EOS (APS-C)
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Page 2 of 3
Distortion
At its default position the Hartblei produces an absolutely negligible degree
of distortion.
80mm:
Vignetting
The Hartblei 80mm MC is a full frame lens so it enjoys the usual sweet spot
effect on an APS-C DSLR resulting in a negligible degree of vignetting.
MTF (resolution)
It is tricky to provide resolution figures for a tilt-shift lens because normally
you don´t tend to use such a lens at default settings (with neither tilt nor shift).
Anyway, here the center resolution is very fine throughout the tested aperture range
with good figures at f/2.8 increasing to even excellent results at f/5.6.
The edges are an entirely different story. At large aperture settings the
results are dismal but there´s an extreme increase in quality at f/5.6 where
the results are good (excellent at f/8). This indicates a rather extreme
field curvature which may not be all that field-relevant because you don´t tend
to shoot flat objects at large apertures. The field curvature may also be a side
compromise of the tilt-shift design.
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
Chromatic aberrations (color shadows at harsh contrast transitions)
are quite low with the Hartblei which is typical for most fix-focal
tele lenses.
Flare
The Hartblei doesn't really seem to perform all that great when in comes to
contra light where it can show quite extreme flare. Surprisingly the flare
effect seems to get worse when stopping down a little (see below).
| f/2.8 |
f/8 |
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Both images kindly provided by Markus Stamm!
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