AY Honors/Optics/Answer Key

2006-10-19T21:21:38Z

71.243.58.35: can it also be called epidioscope?

The '''opaque projector''','''epidioscope''', '''episcope''' or '''epidiascope''' is a predecessor to the [[overhead projector]]. It displays opaque materials by shining a bright lamp, often [[limelight]], onto the object from above. A system of mirrors, prisms and/or imaging [[Lens (optics)|lenses]] is used to focus an image of the material onto a viewing screen. Because they must project the reflected light, opaque projectors require brighter bulbs and larger lenses than overhead projectors. Care must be taken that the materials are not damaged by the heat generated by the light source. Opaque projectors are not as common as the modern "overhead".

Suitable objects included book pages, drawings, mineral specimens, leaves, etc. In the early and mid 20th century, opaque projectors were produced as low cost toy projectors for children, were also marketed as an artist's enlargement tool to allow images to be transferred to prepared canvas, or for lectures and discourses.

==See also==
* [[Projector]] for a directory of projector types.

==External links==

* [http://www.luikerwaal.com/newframe_uk.htm?/epidia_uk.htm Episcopes and epidiascopes], photographs of a collection.
* [http://www.curzon.org.uk/collection/Epidiascope.html Historic Ross Epidiascope]
* [http://adverlab.blogspot.com/2005/03/tools-epidiascope.html Brief description] of the modern [[Braun]] Paxiscope XL Epidiascope.
* [http://www.firstcall-photographic.co.uk/pp/Projectors/35mm_Projectors_and_Epidiascopes/Braun_Paxiscope_XL_Epidiascope.html Another description] of the Braun Paxiscope unit.
* [http://adverlab.blogspot.com/2005/06/epidiascope-strikes-back.html Digital epidiascope] from [[Samsung]].

[[Category:Projectors]]

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AY Honors/Optics/Answer Key