Panasonic LUMIX S 24-105mm f/4 Macro OIS: Evaluating Distortion and the Effects of Distortion Correction
See my L-mount mirrorless wishlist
This page looks at distortion at 24mm, 35mm, 44mm, 71mm, 99mm for the Panasonic 24-105mm f/4 Macro OIS. Few zooms control distortion well (the Canon RF 28-70mm f/2L is a notable exception), and perhaps there does not exist a 24-105mm f/4 zoom that does.
The Panasonic 24-105mm f/4 Macro OIS sets an EXIF flag that requires Adobe Camera Raw to correct for both optical distortion and color fringing. Thus images from Photoshop/ACR or Lightroom always have distortion correction enabled (no choice) for the Panasonic 24-105mm f/4 Macro OIS.
Two questions arise: (1) how much optical distortion is present, and (2) how much does distortion correction degrade micro contrast and sharpness. The latter is particularly relevant to using HighRes mode. So far, I am underwhelmed by HighRes mode, and I suspect that distortion correction is to blame, at least in part.
Panasonic 24-105mm f/4 Aperture Series: Optical Distortion Across the Zoom Range, with/without Distortion Correction
Includes images up to full camera resolution with and without distortion correction, plus crops.