Zeiss Planar T* 85mm f/1.4 ZF - Review / Test Report - Analysis
Lens Reviews - Nikon / Nikkor (APS-C)

Distortion

The Zeiss T* 85mm f/1.4 ZF produces an absolutely negligible degree of distortion (<0.01%).

The chart above has a real-world size of about 120x80cm.

Vignetting

The Zeiss lens exhibited the typical vignetting characteristic for full frame, ultra-large aperture tele lenses used on an APS-C DSLR. At wide-open aperture the vignetting is moderate with 0.6EV. Starting at f/2 the problem is negligible under field conditions.

MTF (resolution)

Similar to most of the other Zeiss ZF lenses the Planar T* 85mm f/1.4 produced outstanding resolution figures in the lab. The center resolution is already excellent at max. aperture whereas the borders are a bit softer but already very good. The contrast is a somewhat "dreamy" at this setting. Between f/2 and f/5.6 the center quality is nothing short of superb. The border quality increases steadily till reaching its (outstanding) peak at f/5.6. At f/8 and beyond diffraction is the limiting factor (as usual). Based on some field the quality seems to decrease significantly at very close focus distances.

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 very moderate varying between an average pixel width of 0.7px and 0.4px at the image borders. Similar to the Nikkor AF 85mm f/1.4D the Zeiss suffers somewhat from purple fringing at large apertures.

Typical for many ultra-large aperture lenses the Zeiss also shows some Longitudinal Chromatic Aberrations (LoCA) resulting in greenish and reddish out-of-focus edge transitions. See also some of the provided sample shots.




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