Monochrome

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Monochrome comes from the two Greek words mono (μoνο, meaning "only" or "alone"), and chroma (χρωμα, meaning "color"). Monochromatic light is light of a single wavelength, or a narrow wavelength range. A monochromatic object or image is one whose range of colors consists of shades of a single color or hue; monochrome images in neutral colors are also known as grayscale or black-and-white.

Theory

In physics, the word is used more generally to refer to electromagnetic radiation of a single wavelength. In the physical sense, no real source of electromagnetic radiation is purely monochromatic, since that would require a wave of infinite duration as a consequence of the Fourier transform's localization property (cf. spectral coherence). Even sources such as lasers have some narrow range of wavelengths (known as the spectral linewidth) within which they operate. In practice, filtered light, diffraction grating separated light and laser light are all routinely referred to as monochromatic. Often light sources can be compared and one be labeled as "more monochromatic" (in a similar usage as monodispersity). And a device which isolates light sources of a narrow bandwidth are called monochromators, even though the bandwidth is often explicitly specified, and thus a collection of wavelengths is understood.

Application

For an image, the term monochrome is usually taken to mean the same as black-and-white or, more likely, grayscale, but may also be used to refer to other combinations containing only two colors, such as green-and-white or green-and-black. It may also refer to sepia or cyanotype images. In computing, monochrome has two meanings:

it may mean having only one color which is either on or off,
allowing shades of that color, although the latter is more correctly known as grayscale.

A monochrome computer display is able to display only a single color, often green, amber, red or white, and often also shades of that color.

In film photography, monochrome is the use of black and white film. In digital photography, monochrome is the capture of only shades of black by the sensor. Originally, all photography was done in monochrome until the invention of color film plates in the early 20th century.

Monochrome

Theory

Application

See also