Re: Human perception of infrared

[Ken Sinclair <photo1@xxxxxxxxxxxxxxx>]

>Bazpan@xxxxxxx wrote:

>> The wavelength of red light is around 750nm. I believe this equates to
>>  0.75mm. If you were to hold a red object such that it almost touched the
>> surface of the eye (say half a millimetre away) you would presumably be able
>> to perceive it as being red. Yet the light reflected from the object would
>> have travelled less than a full wavelength before striking the eye. What
>>am I
>> missing here?

Someone with a REAL steady hand

>I can help a bit here: 750nm is actually .75 micrometers, or
>.00075 mm.
>
>I think the distance of interest is not the distance from
>the red object to the eye, but from the red object to the
>retina.

Surely the distance to eye surface and let the lens "attept" to focus the
light source on the cones in the retina to differentiate the "colour", or
the rods to see the "light".
>
>Well, that's as far as I can go - can anyone with a better
>biophysics background shed some light?
>
>-Aaron

I assume we are talking "red light"  (sorry folks the devil made me type
that one!!!)

Ken


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