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Zeiss Vario-Sonnar T* 24-85mm f/3.5-4.5 N (Contax N to Canon EF) Review / Test Report - Analysis |
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Lens Reviews -
Canon EOS (APS-C)
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Page 2 of 3
Distortion
The level of distortion is comparatively low within the tested APS-C scope. At 24mm the lens shows
only moderate barrel distortion (~1.5%) and at 40mm and 85mm the issue is pretty much negligible.
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Move the mouse cursor over the focal length text marks below to observe the respective distortion
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| 24mm |
40mm |
85mm |
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The chart above has a real-world size of about 120x80cm.
Vignetting
The Zeiss is a full format lens and it shows only a very low degree of vignetting (< 0.5EV)
at wide-open aperture (APS-C DSLR). This is negligible under field conditions.
MTF (resolution)
The Zeiss lens showed a very good and even resolution characteristic throughout
its zoom range. The center resolution is generally very good at wide-open aperture
and excellent beyond (till f/11) whereas the borders stay on a very good level.
The peak performance is reached somewhere between f/5.6 and f/8.
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
generally moderate for a standard zoom lens. As usual the lateral CAs
are most pronounced at the wide end (0.7-1.5px at the borders). The
problem decreases towards the long end of the zoom range and at 85mm
the CAs are not field-relevant anymore.
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