Fujinon XF 14mm f/2.8 R (Fujifilm) - Review / Test Report - Analysis
Lens Reviews -
Page 2 of 3
The produced distortion of the Fujinon is possibly the biggest surprise in this review - it has almost none (0.4% barrel distortion). This is also valid for the RAW data so there's no active auto-correction necessary here.
The light falloff is a different story. In RAW mode the vignetting is rather extreme with a peak of ~2.4EV (f-stops) at f/2.8. Stopping down to f/8 reduces the issue to ~1.3EV which is not that hot either. In JPEG mode, the camera digitally corrects the vignetting down to 1EV at f/2.8 and 0.6EV at f/8. This is acceptable albeit it comes at cost of higher noise in the image corners due to the required "light" amplification.
The Fujinon delivered quite impressive results in the MTF lab. This is especially true for the image center which broke a record in our Fuji lens test section. The results are excellent at f/2.8 and nothing short of outstanding at f/4 and f/5.6. The border region isn't quite as sharp but still good to very good at max. aperture. The sweet spot is reached at f/5.6 with very good results across the frame. Diffraction reduces the quality slightly at f/8 but the lens remains easily usable even at f/11. There is only a marginal amount of field curvature.
The centering quality of the tested sample was very good.
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)
At around 0.4px lateral CAs (color shadows at hard contrast transitions) are minor and nothing to worry about.