Designation:D4086−92a(Reapproved2012)StandardPracticeforVisualEvaluationofMetamerism1ThisstandardisissuedunderthefixeddesignationD4086;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.INTRODUCTIONBecauseperceivedcolorinvolvesthespectralcharacteristicsofsource,object,andeye,differentcombinationsofspectralcharacteristicscanevokethesamecolorsensation.Forthisreason,metamerismhasbeendescribedas“invisiblespectraldifferences.”Apairofspecimensissaidtobemetamericwhenthespecimensmatchunderonesetofilluminatingandviewingconditionsanddonotmatchunderanotherset.Forthisconditiontoexist,theremustbedifferencesinspectralcharacterofspecimensandsourcesorspecimensandobservers.Theremaybemorethanoneconditionunderwhichthespecimensmatch,aswellasmorethanoneforwhichtheyareamismatch.Similarly,twospecimensmaybeanear-matchunderonesetofconditions,andunderanothersetthedirectionandmagnitudeofthecolordifferencemaychange.1.Scope1.1Thispracticedescribesvisualmethodsfordetectingmetamerismandforestimatingthemagnitudeofametamericcolordifference.1.2Thepracticeislimitedtotheconsiderationofilluminantmetamerismandobservermetamerism.Itisnotdesignedtocoverso-calledgeometricmetamerism,inwhichmembersofspecimenpairschangerelativeappearanceastheanglesofilluminationandviewingarechanged,forexample,becausetheyincorporateflakemetalorpearlescentcolorants.1.3Thispracticedoesnotprovideforthecomputationofindicesofmetamerismbaseduponinstrumentalmeasurementofspectralcharacteristics.1.4Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafetyandhealthpracticesanddeterminetheapplica-bilityofregulatorylimitationspriortouse.2.ReferencedDocuments2.1ASTMStandards:2D2616TestMethodforEvaluationofVisualColorDiffer-enceWithaG...
