I am trying to gain some understanding of film curves provided by the manufacturers of the film and I am confused about the Spectral Sensitivity curves. Take this for example (Screenshot of Kodak's Portra 400 PDF)
My thinking is that they give a rough idea of the hue of color produced by the film at different wavelengths by telling you which layers respond to that wavelength. But my question is, how is the film able to reproduce pure blues and oranges? The green layer (magenta-forming) is responding to the wavelengths that make blue (yellow-forming). It looks like all the blues will end up as cyans because of this.
Next, if you look at the wavelengths that result in orange, a lot of that range is only red-sensitive since green layer ends at 600.
So my question is, is there something else going on here not described by the family of 4 curves? Something that causes it to be able to reproduce all the colors? I was trying to think if maybe the orange base plus characteristic curve showing greater DMin for blue, could make up for this. I'm also not sure how the spectral-dye-density curve would affect it.
