Fujinon XF16mm F2.8 R WR review: Resolution, shading and curvilinear distortion
Resolution
The solid red line above tell us centre sharpness improves when the lens is closed down from its maximum aperture of f/2.8 to f/4. The dotted red line reveals there’s a gradual increase in corner sharpness between f/2 and f/5.6, with the sharpest results at the edge reaching their optimum at f/8. Corner sharpness lags some way behind that of centre sharpness and users will find the best edge-to-edge performance around f/5.6. Push beyond f/11 and you’ll notice diffraction starts to affect overall sharpness.
Shading
Vignetting isn’t anything to be too concerned about, with the shading correction that’s built into the file metadata doing a good job of correcting corner shading in raw files when we processed our images through Adobe Lightroom. The corners appear approximately 0.5EV darker than the centre when the aperture is set wide open.