Sep 23, 2024

Practice is Focused on Use with Custom Data Sets

ASTM International’s color and appearance committee (E12) has approved a new standard that will be useful in calculating the colors of objects. The new standard (E3415) expands on color calculations described in ASTM’s standard on CIE colorimetric systems (E308).

According to ASTM member Hugh Fairman, E308 gathered data and pre-calculated weight sets for doing what is called ‘tristimulus integration,’ which determines the actual color of a measured spectral reflectance or spectral power curve. While this standard is still useful in certain cases, a need has grown for the more updated practice described in E3415.

“With the advent of new spectral power distributions, such as LED lighting, and access to additional data-describing observers, such as variation in age and yellowness of lens and retina which are now available, it has become necessary to provide a method for tristimulus integration that lends itself to the use of these custom data sets,” says Fairman.

Fairman notes that, while both E3415 and E308 can be used to obtain identical color information if one starts with identical illuminant and observer data. However, the methods of putting together the sets are different in the two standards.

“There is a section in the new standard that compares the operations of the methods utilized in each of the standards,” says Fairman. “So, while E308 will remain useful well into the future for persons doing routine color control, E3415 will provide means for persons on the cutting edge of color to expand their options into custom illuminants and observers. This will allow them to obtain color information by a consensus-standard methodology such that others using the method will obtain identical color data using identical input data.”

Media Inquiries: Gavin O’Reilly, tel +1.610.832.9618; goreilly@astm.org
Committee Contact: Jamie Huffnagle, tel +1.610.832.9712; jhuffnagle@astm.org

Release #11905

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