Canon EOS R6 Advanced User Guide - Page 200

Diffraction Correction Diffraction (loss of sharpness caused by the aperture) can be corrected. Caution Depending on shooting conditions, noise may be intensified together with the effects of correction. The higher the ISO speed, the lower the amount of correction will be. For movie recording, [Diffraction correction] will not appear. (Correction is not possible.) Note "Diffraction correction" corrects degraded resolution not only from diffraction but also from the low-pass filter and other factors. Thus, correction is also effective for exposures with the aperture wide open. [Diffraction correction] is not displayed when [Digital Lens Optimizer] is set to [Standard] or [High]. Caution General precautions for lens aberration correction Lens aberration correction cannot be applied to existing JPEG images. When using a non-Canon lens, setting the corrections to [Disable] is recommended even if [Correction data available] is displayed. Magnifying the periphery of the image may display parts of the image that will not be recorded. The amount of correction (except diffraction correction) is less for lenses that do not provide distance information. 200