What is metamerism?
Metamerism is a psychophysical phenomenon commonly defined incorrectly as "two samples that coincide with a particular light source and then do not match when illuminated by another light source". In fact, there are several types of metamerism, including a sample, illuminant, observer and geometric. The first two are most often referred and also most often confused. When two color samples seem to match under a particular source of light, but do not coincide under another light source, it is "exemplary metamerism". It can be concluded that the distribution of the spectral reflector of both samples varies slightly and their reflectivity is crossed in at least two areas. Lighting is the lights with considerably different spectral distributions of the power can be indicated and even exaggerated.
Example: Most people have experienced sample metamerism WHEN will wear two socks that seemed to be black while in the bedroom that may have a bulb, but later finding thatOne is black and the other is blue when entering the kitchen that can have a fluorescent lamp. The differences in the distribution of wavelengths between bulbs and fluorescent lights interact with differences in the spectral reflector of the socks curves to appear the same in one light source and different in another.
Explanation: Bulbs in shorter - blue - wavelengths contain relatively small light, and therefore it would be more difficult to distinguish blue colors in such lighting conditions. Fluorescent lighting in the kitchen emits more short wavelengths, and therefore dark blue can easier to distinguish from black. In the bulb are socks "metameric match"; In the fluorescent light, they do not match.
Illuminant metamerism: Illuminant metamerism is witnessing when there are a number of spectrically corresponding - exactly the same - samples, but when everyone is independent but at the same time illuminated and viewed under the lightsThe spectral distribution of performance varies, significant color changes can be perceived. This phenomenon is rarely witnessed, unless a light box is used, which allows the observer to see both lights separated by a divider and two identical samples are illuminated by different light sources.
Example: When visiting the Lighting Department of Large Domestic Improvement Trade, they will often have a bank with distributors between them. Many of the same sample samples from the painting chips department can be placed with one identical sample under each light. The observer can be able to see how every illuminant affects the sample.
metamerism Observer: Each individual perceives the color slightly differently, provided that individuals have a reasonable ability corresponding to color. This can be demonstrated in many ways. Observer metamerism is why 31 individuals tested to derive the "standard observer" from 1931 received ISO, which are still used as the basis for most stUdie Color Science.
geometric metamerism: Identical colors appear different when viewed at different angles, distances, light positions, etc. It can be said that one of the reasons why men and women often perceive color differently is that the distance between female eyes is slightly less than a man. This slightly different angle of stereoscopic point of view falls into the category of geometric metamerism.
Reflections on graphic art and color reproduction: In the printing industry, metamerism is a source of great frustration. Is perceived as a negative characteristic of color; If that did not exist, any believers, problems with color reproduction would be eliminated. In fact, however, it is this phenomenon, which allows the reproduction of the mass color of the work of art.
Explanation: Artists of small oils, pastels, crayons and various dyes and pigments, and each medium has unique spectral reflectance curves. Most color reproductions use azure, purpleRun, yellow and black inks or dyes, although in some cases the printers include several other colors to expand their gamut. However, none of these inks is accurate spectral match with the media originally used to create original art. Therefore, the printed reproduction of the original reproduction of works of art is a metameric match to the original.
Incs used to create color reproduction can be combined to simulate a work of art, but can only be produced to match reproduction only under a single light source (D50 or D65). Metamerism makes it impossible to generate the reproduction of colors that can coincide under the light of the light source. However, without the phenomenon of metamerism, the reproduction of color colors and the color reproduction industry would not be possible, as we know it simply does not exist.