ISO 3664

ISO 3664
Title	ISO 3664
Status	Published
Org	International Organization for Standardization
Date	2009
Domain	Colorimetry, Graphic technology, Photography

ISO 3664 is an international standard specifying viewing conditions for assessing color images and transparencies. It provides requirements for illumination quality, surround, and viewing booth characteristics used by laboratories, printing houses, museums, and photographic studios. The standard is intended to ensure consistency among organizations such as the International Organization for Standardization, national standards bodies, and professional societies involved with color-critical workflows.

Scope and Purpose

ISO 3664 defines standardized viewing conditions for visual evaluation of color prints, transparencies, and related materials to promote reproducibility among institutions like the International Electrotechnical Commission, the European Committee for Standardization, the Royal Photographic Society, and national archives. It addresses parameters such as daylight simulants, correlated color temperature, chromaticity, luminance, and surround reflectance, aligning with other norms published by bodies including the CIE, DIN, and ASTM. The purpose is to reduce subjective variability among evaluators from organizations such as the Getty Conservation Institute, the Library of Congress, the Smithsonian Institution, and the Prado Museum when comparing color-critical artifacts.

History and Revisions

The development of ISO 3664 involved collaboration among experts from committees linked to the International Organization for Standardization, the Commission Internationale de l'Éclairage, and national institutes like the National Institute of Standards and Technology and the British Standards Institution. Early predecessors trace to photographic viewing practices adopted by Kodak, Agfa, and Ilford in the 20th century, and later harmonization efforts with standards from ASTM, CIE, and DIN. Revisions reflect inputs from stakeholders including the Royal Society, the European Commission, conservation professionals at the Louvre, the Metropolitan Museum of Art, and industry players such as Hewlett-Packard, Epson, and Canon. Major updates addressed spectral match of light sources and metrology aligned with laboratories like JRC and institutes such as Fraunhofer.

Technical Requirements

ISO 3664 specifies technical parameters referencing colorimetric frameworks developed by the CIE and measurement methods employed by organizations such as NIST and PTB. Key requirements include a daylight spectral distribution close to a defined CIE illuminant, a correlated color temperature near 5000 K, a specific D65/D50 relationship often considered by museums like the Rijksmuseum and the British Museum, and strict limits on ultraviolet content to protect materials studied by conservators at the National Gallery and the Tate. The standard prescribes minimum luminance levels and uniformity criteria used by printing firms including Heidelberg and Manroland, and mandates surround reflectance values that laboratories at universities such as MIT, ETH Zurich, and Stanford use in visual assessment.

Viewing Conditions and Test Methods

Detailed viewing conditions in ISO 3664 encompass arrangements employed in galleries such as the Uffizi, the Hermitage, and the Prado: light booth geometry, diffuse illumination, and blackout provisions akin to installations at institutions like the Smithsonian American Art Museum. Test methods mirror measurement practices used by metrology labs at PTB, NPL, and NIST employing spectroradiometers and colorimeters from manufacturers such as X-Rite and Konica Minolta. Procedures for verification reference techniques familiar to staff at Kodak Research Laboratories, Fujifilm, and the Royal Photographic Society, including evaluation of metamerism under controlled sources and assessment of surround-induced color perception as studied in experimental psychology departments at Harvard, Yale, and University College London.

Conformance and Certification

Conformance to ISO 3664 is typically assessed by national accreditation bodies such as UKAS, ANSI, and DAkkS, and by third-party certification programs operated by organizations like TÜV, Intertek, and SGS. Laboratories seeking accreditation often follow measurement traceability chains maintained by metrology institutes including NIST, PTB, and LNE. Manufacturers of viewing booths and lamps—companies like Just Normlicht, GTI, and X-Rite—provide equipment specifications and calibration services to demonstrate compliance for clients such as museums, printing plants, and photo labs. Conformance tests commonly include spectral verification, luminance calibration, and surround reflectance checks executed by technicians certified through programs offered by the International Color Consortium and professional bodies such as AIC.

Applications and Industry Adoption

ISO 3664 is applied across sectors that rely on color fidelity: publishing houses like Penguin and HarperCollins, photographic studios for publications of National Geographic and Magnum Photos, printing groups including RR Donnelley and Quad/Graphics, and conservation departments at the Louvre, the British Library, and the Smithsonian. Retail brands with color-sensitive supply chains—examples include Apple, Nike, and LVMH—adopt the standard for proofing and quality control alongside imaging companies such as Canon, Epson, and HP. Adoption is also evident in education and research settings at institutions like the Royal College of Art, the Pratt Institute, and the Bauhaus-Universität Weimar where curricula address color appraisal under standardized lighting.

Criticisms and Limitations

Critiques of ISO 3664 surfaced from stakeholders such as independent photographers, small print shops, and some conservation scientists who reference variability issues raised by groups including the CIE and ASTM. Common limitations cited involve the cost of compliant lighting equipment supplied by companies like Just Normlicht, the practicality of maintaining controlled surroundings in retail environments such as IKEA and Zara, and challenges for online marketplaces including Amazon and eBay in implementing the standard for product photography. Researchers affiliated with institutions like MIT Media Lab, Stanford, and the University of California system have also noted that human visual factors studied at laboratories such as the Max Planck Institute can complicate universal applicability, and that evolving LED spectra necessitate ongoing revisions by standardizing bodies.

Category:International standards