Zeiss Makro-Planar T* 50mm f/2 ZF (FX) - Review / Test Report - Analysis
Lens Reviews -
Nikon / Nikkor (full format)
Tuesday, 27 January 2009 19:29
Page 2 of 3
The Makro-Planar produces only a slight degree (~0.8%) of barrel distortion which isn't really field-relevant.
The chart above has a real-world size of about 120x80cm.
The Makro-Planar may not be as fast as a conventional standard prime lens but it suffers from a similar amount of light falloff at max. aperture (almost 2EV). The vignetting is still visible at f/2.8 and you've to stop down to f/4 in order to resolve the issue.
We're performing our vignetting analysis based on
(uncorrected) JPEGs straight from the camera. The JPG engine of the Nikon D3x features a rather flat
gradation curve, thus has a moderate contrast characteristic, resulting in comparatively low vignetting figures - the
corresponding Canon figures are roughly 40% higher due to the more
aggressive default contrast setting.
Macro lenses tend to be great performers and the Zeiss is no exception to the rule. At wide-open aperture the lens is already extremely sharp in the center whereas the borders/corner are a little softer. The quality increases gradually the more you stop down and the global peak is reached around f/5.6 with an excellent center and very good edge quality. Diffraction is the limiting factor beyond f/8 so even Zeiss cannot fool physics. However, the results are still usable even at f/22.
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
Chromatic Aberrations (CAs)
The Makro-Planar produces a very minimal amount of lateral CAs (color shadows at harsh contrast transitions). This is not field-relevant and an excellent performance in this category.
The quality of the bokeh (out-of-focus blur) is naturally a major aspect for a macro lens. The Zeiss lens does a very good job here. The inner zone of out-of-focus highlights is very evenly rendered. However, due to mechanical vignetting the discs deteriorates to a "cat's eye" shape at large apertures which is less pleasing than the circular shape (which is achieved at smaller apertures). The blur in the focus transition zones is quite smooth.
There's a some bokeh fringing (greenish/purple halos in the focus transition zone) at f/2 but it's not overly disturbing.
The issue is somewhat resolved at f/2.8 and not really relevant anymore from f/4 onwards.
Move the mouse cursor over the f-stop marks below to observe the respective bokeh fringing