Subtractive Light Filter

The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Subtractive Light Filter

 

a type of selective absorption light filter. Colored materials, such as glass, films, and layers of liquids, are used for selective absorption of radiation in any single region of the visible spectrum. The color of each filter is complementary to the color of the light it absorbs. Filters that absorb in the blue region of the spectrum are colored yellow; green-absorbing filters are purple, and red-absorbing filters are azure.

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.