Difference between revisions of "CdS"
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| − | '''CdS''' — Cadmium Sulphide | + | {{glossary}} |
| + | {{Flickr_image | ||
| + | |image_source= http://www.flickr.com/photos/dbroglin/3130881286/in/pool-camerawiki | ||
| + | |image= http://farm4.static.flickr.com/3248/3130881286_f7d372a133.jpg | ||
| + | |image_align= right | ||
| + | |image_text= CdS meter cell mounted on [[pentaprism]] of [[Kowa SE]] | ||
| + | |image_by= David Broglin | ||
| + | |image_rights= with permission | ||
| + | }} | ||
| + | '''CdS''' — Cadmium Sulphide. In a photographic context, this refers to an electronic [[light meter]] using a CdS sensor, which varies its electrical resistance in response to the brightness of the scene. CdS meters became common in the 1960s, largely replacing [[Selenium]] cells, which required a much larger light-collecting area. While Selenium cells which generate their own electricity, CdS meters require a battery. CdS meters are sufficiently power-hungry that with most designs some form of switch is provided to turn off the meter circuit, to conserve battery life. (In a few cases, the photographer is simply expected to cap the lens; in darkness the current flow drops to a minimum.) | ||
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[[Category: stub]] | [[Category: stub]] | ||
[[Category: meters]] | [[Category: meters]] | ||
Revision as of 17:50, 8 May 2011
Glossary Terms
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| CdS meter cell mounted on pentaprism of Kowa SE image by David Broglin (Image rights) |
CdS — Cadmium Sulphide. In a photographic context, this refers to an electronic light meter using a CdS sensor, which varies its electrical resistance in response to the brightness of the scene. CdS meters became common in the 1960s, largely replacing Selenium cells, which required a much larger light-collecting area. While Selenium cells which generate their own electricity, CdS meters require a battery. CdS meters are sufficiently power-hungry that with most designs some form of switch is provided to turn off the meter circuit, to conserve battery life. (In a few cases, the photographer is simply expected to cap the lens; in darkness the current flow drops to a minimum.)
