colour filter

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References

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Salem Witch Trials. Photogravure after the painting by Walter McEwen titled - The Witches - circa 1890s.

How Rye Bread May Have Caused the Salem Witch Trials

pulmonary veins and arteries, circulation, cardiovascular system, human anatomy, (Netter replacement project - SSC)

13 Questions About How the Human Body Works Answered

Queen Elizabeth II addresses at opening of Parliament. (Date unknown on photo, but may be 1958, the first time the opening of Parliament was filmed.)

All 119 References in “We Didn’t Start the Fire,” Explained

Time zone map with standard time zones and International Date Line

Why Are Some Time Zones 30 Minutes Off Instead of an Hour?

The impeachment trial of Pres. Andrew Johnson, illustration from Frank Leslie's Illustrated Newspaper, March 28, 1868.

What If the President Is Impeached?

San Francisco, California/USA-1/18/20: Womens March at Civic Center marching with signs of political protest regarding equality also embracing 2020 presidential candidates and celebrating equality

How Does the U.S. Government Define the Difference Between a Protest and a Riot?

Normandy Invasion: Omaha Beach. World War II. D-Day. Infographic. SPOTLIGHT VERSION

Facts and Figures About the Landings on Omaha Beach During the Normandy Invasion on June 6, 1944

colour filter

optics

Learn about this topic in these articles:

optical engineering

In optics: Filters and thin films
A colour filter is a sheet of transparent material that modifies a light beam by selective absorption of some colours in relation to others. A neutral filter absorbs all wavelengths equally and merely serves to reduce the intensity of a beam of light without changing its…
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