Colorimetry
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Colorimetry is the science that describe colors in numbers, or provides a physical color match using a variety of measurement instruments, depending on the desired information about the color or colors the customer requires.
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Who uses colorimetry?
It is an important analytical technique in varying fields, including chemistry, color printing, textiles, paint manufacturers, and many more.
Overview of the instuments
They may use a colorimeter, which takes only 3 wideband readings along the visible spectrum to obtain a rough estimate of a color sample. For critical color matching a spectrophotometer that takes readings 31 times along the visible spectrum would be employed. Sometimes all the customer needs is a density (how light or dark) reading, in which case a simple densitometer would suffice. If they were analyzing a light source a spectroradiometer, which acts much like the spectrophotometer, only it can handle the bright light source that they were to measure.
Range of challenges in colorimetry
Colors that look the same seldom have the same spectral characterisitics in any colorimetric system you employ, even assuming identical viewing conditions and identical observers with normal color vision. See Metamerism (color). Spectrophotometry spectral power distributions spectral reflectance
The measurement devices - in depth
Color can be measured using a spectrophotometer, which takes measurements in the visible region (and a little more on both ends,) to generate a spectral reflectance curve of a given color sample. The spectral reflectance curve is the most accurate data that can be provided regarding a color's characteristics. However, a spectral refelectance curve is a graph of 31 readings taken at 10 nanometer increments along the electromagnetic spectrum from 400 to 700 nanometers. The plot is often referred to as the DNA of the color. However, what practical application do 31 values have? This is why the values are mathematically reduced to 3 values via a very long calculation that integrates the "standard observer" and your chosen light source, ending up with 3 tristimulus values, which need to be converted yet again into some easier to understand coordinate in a color space of your choosing. Just remember, 31 values reduced to 3 can never create a perfect result in any field of science. Explanation below:
Explanation:Colorimetry utilzes the standard color science calculations provided by the (Commission Internationale De l'Eclairage) the International Lighting Standards Commission CIE provided in 1931. Colorimetry is not an exact science due to the limitations inherent in the system. Metamerism being the most troublesome. The design of the measurement devices, and their values used to estimate a given light source,etc.
In some industries they use only a row of pigments, a color to which they are told to match, color correct lighting. and their hands and eyes. Silkscreen experts often find the science of colorimetry to be useless, for many can mix the required color in under 10 minutes.
The customer with their particular eyes is whom businesses aim to please. It's crucial to begin by evaluating the actual complexity of the challenge before beginning the task at hand.fr:Colorimétrie