Reality Creation is Sony’s dynamic detail enhancement and sharpening feature. In the old days, the challenge for a projector was to simply to be sharp, to faithfully reproduce that which was on the source material. But in the last several years, as image processing improved dramatically, the new “thing” seems to be to go beyond. That is, to image process to put back in – to the best of a projector’s ability, what was lost in the process of delivering the original content on a lower resolution than original (1080p) projector, thus to try to get the home experience closer to the theater one. RC when on, defaults to a setting of 20 out of 100 (at least in most modes). Depending on content, I find I can enjoy it pushed to 40 but not much higher – some content I can push it to 50-60, but not much, at least if I don't want the processing to be a bit obvious (fine for sports, for example).
The interesting thing is that RC works with 4K content as well. You likely won’t mess with it too much, at all, with 4K content. I stuck to 20, except for specifically when I was playing with it to see the affects of different settings.
In the images in this gallery, the first two pair (full and close-up) are from HDTV, the last pair is 4K from a Blu-ray UHD source.
Bottom line: RC takes your content, be it 1080 or 4K, and makes it seem sharper. (Apply as necessary!)