Re: A Lens?

> Guillermo writes

> BTW, taking about ZP, there is an article in that Shutterbug Feb/2001
> edition about some Canon glass lenses using Diffractive Optics, the same
> principle ZP lenses use. This new lenses (no yet released) use fresnel
> lenses in combination with glass lenses.

    I thought the Shutterbug article completely confused diffraction
    and refraction, since a fresnel lens works by ordinary lens refraction
    and not by diffraction. The Canon lens could have a diffractive
    element of some kind and it would be interesting to see the Canon
    explanation rather than the garbled Shutterbug article.

    Nikon has a couple lenses with movable internal elements that
    control the spherical aberation. They call it Defocus Control
    and the effect is something like the Dreamagon lens.
Received on Thu Jan 18 09:50:39 2001