Colorimetry

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Colorimetry is the science of defining and measuring colors in a way that will correlate to how an "average" person will see the color. Precisely defining and measuring colors is needed in chemistry, color printing, paint manufacturing, textile manufacturing and advertising. For example, you would not want to buy two colors of the same paint and discover that they are noticeably different.

This science has to be quite accurate, since people are said to be able to recognize over 16 million different colors. That means, as in the case of painting your house, the two cans of paint better match exactly or you are likely to notice the difference.

Defining and measuring colors is difficult since each and every person sees color a little differently. To this end, researchers have tested thousands of people to determine how each perceives color, and combined their results to create a "standard observer" or the average person's sensitivity to various lights and colors.

Even though we each perceive colors slightly differently, the International Commission on Illumination or CIE (abbreviation for its French name, Commission internationale de l'éclairage) has devised a standardized technique for defining and measuring colors using the data for a standard observer.

But even with all our modern technology, it is difficult to measure colors exactly due to the human element (slightly different perceptions) and the fact that the light source can cause a perceived change in color due to color temperature. Another difficulty relates to metamerism which is how two colors can appear to match exactly even though they may be significantly different when viewed with special equipments, since they are comprised of different spectral power distributions. In other words, because of the light source and metamerism, two colors that are not the same may look the same and two colors that are exactly the same may look different under different lighting conditions.

The Instruments

There are four main classes of instruments used in colorimetry, the colorimeter, spectrophotometer, densitometer, and spectroradiometer.

Colorimeter

A colorimeter makes a rough estimate of the color by taking three wideband readings. The readings are taken along the visible spectrum. The size of the filter is extremely important. The wavelength of light which it transmits must equal that which is absorbed by the substance.

Spectrophotometer

A spectrophotometer is used for critical color matching. It takes 31 readings along the visible spectrum. The plot produced using this device is often referred to as the DNA of the color. The 31 values are reduced mathematically to 3 tristimulus values which are converted to coordinates in a desired color space.

Densitometer

A densitometer measures lightness and darkness.

Spectroradiometer

A spectroradiometer is used to measure the colors of the light source.

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  "toaff" Code for affiliate links. Put this in for all affiliate links in case we need to find them.

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Alternative - Open New Window - link that is a different way to have it open a new window

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Cells are sized by the largest cell in a column. To make the cells larger, put nbsp in them. But make every other one a regular space (use a space in the text) becuase it takes less code and allows a carriage return to be inserted if someone's screen is small. Otherwise, they will have to scroll back and forth.

If no table border (tb1, ex.) is defined, the default is tb0, or no border around the cells.

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To have a different background color, go to cssoptions in IncColors and put an X in colorsbg to enable this feature. Define the class for the bg color.

To have no borders:

• Do not define a border (ex., tb1). The default is no border.
• Define style="background:#xxxxxx" where xxxxxx = the color code of the bg color.

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The first essential to the application of the Munsell Color System is a clear understanding of the three dimensions of color. Once the simple logic of these dimensions is grasped, the practical advantages of the Munsell System will be apparent.

Example of linking to a Named Anchor:

www.SiteName/PageName/index.php#ManMadeDiamonds

To Redirect a File:

Open an existing php file using NoteTab. Delete everything and replace it with the following code. Save with NoteTab, making sure it is still a php file.

function redirect($to)
{
$pc = $_SERVER['SERVER_PORT'] == '443' ? 'https' : 'http';
// $host = strlen($_SERVER['HTTP_HOST'])?$_SERVER['HTTP_HOST']:$_SERVER['SERVER_NAME'];
if (headers_sent()) return false;
else
{
// header("HTTP/1.1 302 Found"); HIGHLY SUGGESSTED YOU DONT USE THIS !!!!!!!!
// header("HTTP/1.1 303 See Other");
header("HTTP/1.1 301 Moved Permanently");
header("Location: $pc://$to");
exit();
}
}
?>

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