Samsung NX 85mm f/1.4 ED SSA - Review / Test Report - Analysis
Lens Reviews -
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Medium tele prime lenses don’t tend have issues with distortion and that’s also true for the Samsung NX 85mm f/1.4. It produces only a negligible degree of barrel distortion (0.2%).
The vignetting characteristic of the Samsung lens is pretty decent. It shows some light falloff at f/1.4 but the issue is not extreme. The vignetting is substantially reduced at f/2 and not relevant anymore from f/2.8 onward.
Ultra-large aperture lenses tend to have corner issues at large aperture settings but Samsung managed to overcome this shortcoming in the NX 85mm f/1.4. The center performance is very nice at f/1.4 but even the borders and corners are good to very good. Stopping down improves the performance slightly reaching its peak in a broad range between f/2.8 and f/8. The center quality is excellent here followed by a very good border/corner region. Diffraction reduces the quality from f/11 onward.
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)
Lateral CA (color shadows at the image borders) are very well controlled with an average pixel width of less than 0.8px. This may be just visible but not disturbing.
A very important aspect of an ultra-large aperture lens is the quality of the bokeh (rendering of the out-of-focus blur). The NX 85mm f/1.4 impressed us quite a bit here.
The foreground blur is just slightly nervous but the more important background blur is very smooth.
Out-of-focus highlights have an even inner zone. They are circular in the image center but slightly "cat’s eye shaped" in the corners (a vignetting effect). Stopping down improves the cat’s eyes and the circular shape remains intact including f/2.8.
Bokeh Fringing / Longitudinal Chromatic Aberrations (LoCA)
Bokeh fringing is a common issue with fast glass. It's visible as halos of different colors in out-of-focus areas - magenta (red + blue) in front of the focus point and green beyond.
The NX 85mm f/1.4 shows noticeable bokeh fringing at large aperture settings which can of be reduced by stopping down. The effect remains slightly visible even at f/2.8 but it is basically gone from f/4 onward.
Move the mouse cursor over the f-stop marks below to observe the respective LoCAs