Re: Chromatic abberation + IR

[Goff Photo <jdgoff@xxxxxxxx>]

At 04:55 PM 4/22/97 +0100, you wrote:
>
>On Tue, 22 Apr 1997 pbadcock@xxxxxxxxxxxxxxx wrote:
>
>> one, well I think I did.  I'm assuming that the majority of your lenses
>> these days have special coatings on them to avoid chromatic abberation
>> in the visible range, This attempts to correct for the fact that light
>> of different colors refracts through the lens(es) at different angles.
>
>As far as I know, the coatings on lenses do not correct for chromatic
>abberation.  Rather they are there to reduce internal reflection and lens
>flare.  Chromatic abberation is I believe dependent on the lens design
>rather than the antireflection coatings used.
>
>- Wayde
>  (allen@xxxxxxxxxxxxxxxx) 
>
You are correct. Chromatic abberation is the lack of a lens' ability to
focus all wavelengths at the same plane. Lens coating is to reduce internal
reflection, as you said. Apochromatic lens are designed to correct almost
completely for chromatic abber.
>


------------------------------