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A comment on Metamaterial based flat lens promises possible revolution in optics. Parent comment

Re:Metamaterial based flat lens promises possible revolution... by alexbock on Friday June 03, 2016 @01:34PM (#11831801)
The difference is that they were using film which was sensitive over the entire visible spectrum with color filters that allowed a broad range of wavelengths that are all perceived as the same color. If you had a smartphone camera filtered with a 1 nm bandpass filter for a particular wavelength, you're going to get so little light that it will be like taking pictures in the dark.

The filter approach is still used in most cameras (Bayer filters) but a vary narrow wavelength bandpass would not be appropriate for a consumer camera.

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Re:Metamaterial based flat lens promises possible revolution... by colanderman on Friday June 03, 2016 @01:41PM (#11831855)
Amount of light aside, the color rendition would be horrible too. Akin to the light from an RGB LED panel.
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Re:Metamaterial based flat lens promises possible revolution... by dingo_bat on Saturday June 04, 2016 @02:45AM (#11835266)
What's wrong with the color rendition of RGB panels? The newest ones are some of the most color accurate displays available.
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Re:Metamaterial based flat lens promises possible revolution... by colanderman on Monday June 06, 2016 @11:11PM (#11852132)
I don't mean the images displayed on a panel; I mean the light from the panel if it were used to illuminate something else. Because you have only three narrow wavelengths of light, you lose 99% of the color information contained in the illuminated object's absorption spectrum.

Actual LED lamps work around this issue by using phosphors to broaden the spectrum.

This quality of light is measured by the Color Rendering Index; the phenomenon of color differences due to narrowband light sources is known as metamerism.

The images displayed on a panel do not suffer this issue, because our eyes can detect only 3 "dimensions" of color; hence 3 narrowband illuminants suffice. (And in fact narrowband is necessary for a broad color gamut.) It is only when reflection/absorption comes into play that metamerism matters.

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