From the Killzone SF lighting video they showed a diagram at 12min and said that for metals they are changing the fresnel reflection and specular from 0-90 degrees of incidence per wavelength. Throughout the video they use aluminum, copper, gold, iron, silver, and titanium material examples. Where can I find a chart of…
Well, that diagram you linked has a reference chart in it. So I'd guess there is probably a good place to start. Or if you want to go full math-mode, start googling IOR/RI lookup tables.