LG CX OLED ideal sharpness setting

tl;dr:

4K:

• Sharpness: 0
• Super Resolution: Off

Anything else:

• Sharpness: 12
• Super Resolution: Low

Explanation:

0 sharpness passes through the image untouched, which would normally be desirable, but not when the upscaler has produced an image that is far from untouched. PC mode with RGB input is the only time the upscaler results could be considered untouched.

10 sharpness applies an anti-aliasing filter, but does NOT apply any actual sharpening. Counter-intuitively, 10 sharpness is effectively softer than 0 sharpness.

Smooth Gradation set to Low adds additional softening and some debanding, so you may want it set, but I find the loss of noise and detail too unpleasant and instead keep it off. It is bad at its intended purpose of smoothing gradients, other than in heavily compressed content.

The effect of Super Resolution is diminished until sharpness is raised above 10. 12 is a reasonable middle ground to get the super resolution effect without introducing traditional sharpness artifacts that exist in settings above 10, but you could go as high as 15 or 20 depending on taste. Raising the sharpness also reduces the difference between areas of excessive sharpening from the upscaler and the rest of the picture. I find a mildly oversharpened picture more pleasing to the eye than a picture with specific areas of oversharpness.

Previously this guide recommended Super Resolution set to Medium, but on reflection I have determined this creates an unnatural rough-looking texture on skin in HD sources, and accentuates artifacts in SD. Low looks more comparable to madVR and professional upscales (DCI 2K upscaled ('fake') 4K Bluray releases).

PC mode applies a more basic upscaling algorithm and effectively disables the AI upscaling. It is the only way of controlling (disabling) the AI upscaling. You can verify if PC mode is engaged properly as the settings for Noise Reduction and Smooth Gradation should be greyed out. In PC mode at 1440p or less you can consider setting sharpness to 0 or 10 (0 for passthrough, 10 for anti-aliasing) instead of 12. For video games I stick with 12.

My target with these settings is to get upscaled inputs looking somewhere between trivial upscaling algorithms and madVR. Even text content being fed to the TV at 1080p/1440p looks better with these settings - they work for all cases.