Zeiss Vario-Sonnar T* 24-85mm f/3.5-4.5 N (Contax N to Canon EF) Review / Test Report - Analysis
Lens Reviews -
Canon EOS (APS-C)
Page 2 of 3
The level of distortions is comparatively low within the tested APS-C scope. At 24mm the lens shows
only moderate barrel distortions (~1.5%) and at 40mm and 85mm the issue is pretty much negligible.
Move the mouse cursor over the focal length text marks below to observe the respective distortions
The chart above has a real-world size of about 120x80cm.
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.
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.
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.
The chart is limited to the visually relevant LW/PH range of [750, 2250].
If you want to know more about the MTF50 figures you may check out the corresponding
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.