| Reducing opacity might work, but my suggestion is to use a layer mask.
As for eyes vs. hair, fine detail will be the first thing lost. Eyes are only saved by virtue of their being bigger. But you can overlay the real hair and set the blend mode to darken and the full detail should be restored.
It's a blurring method, the actual math is proprietary. But I suspect some sort of luminosity blur, perhaps with some edge detection.
As for looking fake, it depends on how much you crank it up. It's a plugin, so it will never replace actual skill and experience. I doubt any major outlet would use this or any other plugin. But the idea is to look flawless, which is by definition "fake". |