On Feb 2, 8:50=A0pm, Logan Kearsley <chronosur...@[EMAIL PROTECTED]
> wrote:
> A white light source will produce different colors in a thin film
> depending on the angle of the light source.
> So, by simply sandwiching a flat retina between a thin transparent
> layer and a reflector, one could get a very simple eye that's
> incapable of imaging but which can use color to detect the angular
> position of a light source (or the source of a shadow).
> It would, however, be subject to confusion when looking at brightly
> colored objects- especially other iridescent objects, which might
> appear to jump around the visual field as their apparent color
> changes.
I don't think this idea can work unless there's only one light
source, and it's more or less a point light source. Also,
in order to get any information at all the color sensors need
to be filtered to only receive narrow bands of frequencies.
That means severely limited sensitivity. The way our color
vision works, each light receptor accepts a relatively broad
band of frequencies. This makes our vision more sensitive
to differences in brightness rather than differences in color,
but it also makes our eyesight more sensitive.
> So, I wonder if there is any function or environment in which that
> would not be a fatal flaw. Is there some reason that an alien or
> genetically engineered creature might rely on an iridescence eye?
Even assuming the iridescence eye works just fine, I don't
see how useful the information is. Knowing a light source
is along the surface of some cone doesn't seem as useful
as, say, knowing whether the light sources is vaguely to the
left or vaguely to the right. The latter information may not
be precise, but it's enough to crudely hunt down or avoid
the light source. With the information your sensor provides,
you can't even do that.
Isaac Kuo
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