From: Marc Nicholas Subject: Re: TECH: Holographic optics? Date: Mon, 19 Apr 1993 15:55:51 GMT Organization: RedNet - The Mac Networking People >thinman@netcom.com (Technically Sweet) writes: > >>diego@minerva.st.dsi.unimi.it (Diego Montefusco) writes: >> >>>In Pimentel and Teixeira's book there's an interesting thing I never >>>heard about before: they say it is possible to duplicate a complex set >>>of optics on inexpensive, lightweight plastic film via an appropriate >>>hologram (pg.109). >> >>No info on this, but a recent Scientific American reported on using >>semiconductor etching tech to customize diffraction gratings. >>Diffractive optics can simulate existing optical lenses and can do >>all-new effects that optics can't handle. This may be the key to >>getting the optics right in HMD's. > >I'm pretty sure that article was on _digital lenses_, which are >consiferably different than holographic lenses. Holographic lenses >are much more sensitive to the color of the light they pass than >normal lenses. The digital lenses use localized geometry, combining >the curvature of normal lenses with the steps of Fresnel lenses. Diego is right...they were referring to "holographic lenses" as opposed to the regular optics (ie. Fresnal lenses etc.). It strikes me that if it were so easy, everyone would be doing it! Dave: didn't you build your own HMD? Please share details! Marc :)