Nikon NIKKOR Z 20mm f/1.8 S: Assessing Sharpness Losses from Mandated Distortion Correction
The Nikon Z7 requires distortion correction (and lateral chromatic aberration correction) for the Nikon NIKKOR Z 20mm f/1.8 S by setting a flag in the EXIF. This requirement guarantees sub-optimal micro contrast and sharpness in a substantial portion of the outer zones of the frame due to the stretching-apart of pixels, although central areas remain at least as good.
In order to see the differences between the uncorrected and distortion corrected image, I used Iridient Developer, which unlike Adobe Camera Raw allows selectively enabling or disabling corrections regardless of the EXIF flags that mandate a correction.
Nikon NIKKOR Z 20mm f/1.8 S Distortion and Distortion Correction
Includes images up to full camera resolution, plus crops.
Below, toggle to compare uncorrected to corrected.