Get Nikon Z at B&H Photo.
It’s really annoying to read about features in which Nikon makes no mention of whether it applies to both RAW and JPEG.
Do people really spend $5000+ on a camera system and shoot JPEG?
My presumption is that diffraction compensation applies only to JPEG since the page that follows discusses Picture Control, which is irrelevant for RAW.
From the Nikon Z7 brochure:
EXPEED 6 also offers diffraction compensation, which helps capture landscapes and cityscapes crisply even at slow apertures. And with the introduction of Creative Picture Controls, it enables you to create your own look more easily than ever before.
With digital cameras, if you select a small aperture to increase depth of field when shooting cityscapes or landscapes, it may cause a loss of sharpness across the image due to diffraction. The Z 7’s newly employed diffraction compensation function automatically reduces the effects of diffraction when a small aperture is used. As a result, you can get the most out of the high resolving power of NIKKOR Z and NIKKOR F lenses and the camera’s high-pixel-count image sensor.
It is so sloppy to not insert (“JPEG only”) if that is the case.