1、| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | BRITISH STANDARD BS ISO 6328:2000 ICS 37.0
2、40.20 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW Photography Photographic materials Determination of ISO resolving powerThis British Standard, having been prepared under the direction of the Consumer Products and Services Sector Committee, was published under the authorit
3、y of the Standards Committee and comes into effect on 15 June 2000 BSI 06-2000 ISBN 0 580 36001 6 BS ISO 6328:2000 Amendments issued since publication Amd. No. Date Comments National foreword This British Standard reproduces verbatim ISO 6328:2000 and implements it as the UK national standard. The U
4、K participation in its preparation was entrusted to Technical Committee CPW/42, Photography, which has the responsibility to: aid enquirers to understand the text; present to the responsible international/European committee any enquiries on the interpretation, or proposals for change, and keep the U
5、K interests informed; monitor related international and European developments and promulgate them in the UK. A list of organizations represented on this committee can be obtained on request to its secretary. Cross-references The British Standards which implement international or European publication
6、s referred to in this document may be found in the BSI Standards Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Find” facility of the BSI Standards Electronic Catalogue. A British Standard does not purport to include all the necessary provisions
7、 of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, the ISO title page, pages ii to v, a
8、blank page, pages 1 to 15 and a back cover. The BSI copyright notice displayed in this document indicates when the document was last issued.Referencenumber ISO6328:2000(E) INTERNATIONAL STANDARD ISO 6328 Secondedition 2000-05-01 PhotographyPhotographicmaterials DeterminationofISOresolvingpower Photo
9、graphie Surfaces sensibles Dtermination du pouvoir rsolvant ISOISO6328:2000(E) ii ISO6328:2000(E)iii Contents Page Foreword.iv Introduction.v 1 Scope1 2 Normativereferences1 3 Termsanddefinitions.1 4 Samplingandstorage.3 5 Testmethod3 6 Productclassification.13 7 Productmarkingandlabelling.14 AnnexA
10、(informative)Illustrationofanexampleofaresolving-powercamera15ISO6328:2000(E) iv Foreword ISO(theInternationalOrganizationforStandardization)isaworldwidefederationofnationalstandardsbodies(ISO memberbodies).TheworkofpreparingInternationalStandardsisnormallycarriedoutthroughISOtechnical committees.Ea
11、chmemberbodyinterestedinasubjectforwhichatechnicalcommitteehasbeenestablishedhas therighttoberepresentedonthatcommittee.Internationalorganizations,governmentalandnon-governmental,in liaisonwithISO,alsotakepartinthework.ISOcollaboratescloselywiththeInternationalElectrotechnical Commission(IEC)onallma
12、ttersofelectrotechnicalstandardization. InternationalStandardsaredraftedinaccordancewiththerulesgivenintheISO/IECDirectives,Part3. DraftInternationalStandardsadoptedbythetechnicalcommitteesarecirculatedtothememberbodiesforvoting. PublicationasanInternationalStandardrequiresapprovalbyatleast75%ofthem
13、emberbodiescastingavote. AttentionisdrawntothepossibilitythatsomeoftheelementsofthisInternationalStandardmaybethesubjectof patentrights.ISOshallnotbeheldresponsibleforidentifyinganyorallsuchpatentrights. InternationalStandardISO6328waspreparedbyTechnicalCommitteeISO/TC42, Photography. Thissecondedit
14、ioncancelsandreplacesthefirstedition(ISO6328:1982),whichhasbeentechnicallyrevised. Inthisrevision,thedescriptionoftheprocessofevaluatingimageshasbeenexpanded.Thespecificationsofthe resolvingpowercamerasobjectiveshavebeenalteredslightly,andtheillustrationofaresolving-powercamera hasbeenmovedtoinforma
15、tiveannexA.Thetextdescribingqualificationofthecamerahasbeenexpandedto includethetarget. Thissecondeditionalsocontainsmanyotherchanges,mostofwhichweremadeforthesakeofclarityof understanding.Amongthesechangesisaclarificationofpartofthescope.Thedefinitionshavealsobeen expanded;sometermshavebeensubstitu
16、tedforothersinorderfortheirusagetobemoreconsistentandtheir meaningtobeclearer.Theterm“element”hasbeenintroducedinplaceof“testpattern”and“tribarresolving- powertarget”replaces“testchart”.Othertermsintroducedorclearlydefinedinclude“targetpolarity”,“limiting element”and“ISOresolvingpower”. AnnexAofthis
17、InternationalStandardisforinformationonly.ISO6328:2000(E)v Introduction Theresolvingpowerofaphotographicmaterialisusedtoestimatethesmallestdetailthatmaybevisually observablewhenrecordedonthematerial.Itcombinestheeffectsofmodulationtransferfunction,graininessand contrast,allofwhichcontributetooverall
18、imagequality,andhumanobservers,eachofwhommaydifferintheir assessmentofquality. Themethodisparticularlyusefulforappraisingmaterialsthatwillbeviewedathigh magnificationsuchasmicrofilm,8mmand16mmmotionpicturefilm,etc.However,resolvingpowershouldnot beexpectedtopredictoverallimagequalityineverysituation
19、,becauseimagequalityistoocomplextobe describedbyasinglefactor.Thisisparticularlythecaseforlow-contrastcontinuous-toneproducts. Resolvingpowerasmeasuredbyphotographingsuitabletribarresolving-powertargetsisverydependenton conditionsofmeasurement,andthestructureofthetargetelement.Itdependsmarkedlyonthe
20、photographic conditionsemployedandonthepresenceofbackgroundglarefromtheilluminatedtarget.Itisaffectedbysuch factorsasthespectralcontentofthelightused,theexposurelevel,thefocus,processingprocedures,thelens apertureatwhichthetestismade,thecontrastofthetargetandthemagnificationofthecameralensandthe mic
21、roscopethroughwhichtheimagesareobserved,etc. Thejudgmentexercisedbythehumanobserverindeterminingresolvingpowercanbeasourceofsignificant experimentalerror. ThecriterionofresolutiongiveninthisInternationalStandardwasselectedbecauseit appearedtoadmitlesslatitudeininterpretationthanothers.Thedescription
22、oftheprocessofevaluatingimages hasbeenexpandedinthisrevision.INTERNATIONALSTANDARD ISO6328:2000(E)1 PhotographyPhotographicmaterialsDeterminationofISO resolvingpower 1 Scope ThisInternationalStandardspecifiesamethodfordeterminingtheresolvingpowerofphotographicfilms,plates andpapers,includingblack-an
23、d-whitefilms,black-and-whiteprintingpapers,colour-reversalfilms,colour-negative films,andcolour-printingpapers. MaterialsdesignedforX-rayandotherhigh-energyradiationareexcluded,asarephotographicmaterialsusedin medicalradiographywheretheexposuresourceisanintensifyingscreenincontactwiththefilm(sensiti
24、zedonone ortwosides).Alsoexcludedarematerialshavingphoto-polymer,diazo,etc.light-sensitivelayers. 2 Normativereferences Thefollowingnormativedocumentscontainprovisionswhich,throughreferenceinthistext,constituteprovisionsof thisInternationalStandard.Fordatedreferences,subsequentamendmentsto,orrevisio
25、nsof,anyofthese publicationsdonotapply.However,partiestoagreementsbasedonthisInternationalStandardareencouragedto investigatethepossibilityofapplyingthemostrecenteditionsofthenormativedocumentsindicatedbelow.For undatedreferences,thelatesteditionofthenormativedocumentreferredtoapplies.MembersofISOan
26、dIEC maintainregistersofcurrentlyvalidInternationalStandards. ISO497:1973, Guide to the choice of series of preferred numbers and of series containing more rounded values of preferred numbers. ISO554:1976, Standard atmospheres for conditioning and/or testing Specifications. 3 Termsanddefinitions For
27、thepurposesofthisInternationalStandard,thefollowingtermsanddefinitionsapply. 3.1 element threeparallelbarsandtwospacesofequalwidthandseparation 3.2 groupnumber numberofsquaredotsprecedingthearrayofelementswhichisusedtolocateapositiononthetribarresolving- powertarget 3.3 tribarresolving-powertarget a
28、rrayofidenticalelementsthatdecreaseinsize(geometrically),andtypicallyspiralstowardsthecentreofthe targetformat 3.4 spatialperiod withinanelementofatribartarget,thedistancebetweentheleadingedgesoftwoconsecutivebars NOTE Thespatialperiodisusuallyexpressedinmillimetres(mm).ISO6328:2000(E) 2 3.5 spatial
29、frequency reciprocalofthespatialperioddenotingthenumberofidenticalbarandspacepairsthatcanbecontainedwithinan overallwidthof1mm NOTE Thespatialfrequencyisexpressedasreciprocalmillimetres(cyclespermillimetre). 3.6 contrastratio ratiooftheluminancesofthebarsoftheelementtotheluminanceofthesurroundorthea
30、ntilogofthedensity differencebetweenthebaranditssurround 3.7 targetpolarity transmissionrelationshipoftheparallelbarsandtheirsurround 3.7.1 negativepolarity lightbarsagainstadarksurround 3.7.2 positivepolarity darkbarsagainstalightsurround 3.8 camera opticalsystembywhichthetribarresolving-powertarge
31、tisimagedandrecorded,withsuitablereductioninsize,on thephotographicmaterialbeingtested 3.9 referencesurface flatsurfaceagainstwhichtheemulsionsideofthephotographicmaterialispressedduringexposure 3.10 qualification camera attainmentofthenecessaryhighopticalperformanceofacamera,essentialforitsuseindet
32、erminingresolving power 3.11 replicateset seriesofimagesofthetribarresolving-powertargetmadeatthesamefocusandexposuresettings 3.12 exposureseries seriesofimagesmadeatdifferentexposuresettings 3.13 focusseries seriesofimagesmadeatdifferentfocussettings 3.14 resolvingpower abilityofaphotographicmateri
33、altomaintain,inthedevelopedimage,theseparateidentityofparallelbarswhen theirseparationissmall NOTE Theresolvingpowerisnumericallyequaltothespatialfrequencyofthesmallestelementthatcanberesolved.ISO6328:2000(E)3 3.15 limitingelement thatelementintheimageofthetribarresolving-powertargetselectedbytheobs
34、erver,withreasonableconfidence, tobeatthethresholdofnolongerbeingabletodistinguishthreebarsandtwospaces,evenifthenumberwerenot knowntobethree 3.16 resolvingpowerofareplicateset medianoftheresolving-powersofthetestmaterialinimagesofthereplicateset 3.17 maximumresolvingpower resolvingpowerofthetestmat
35、erialunderconditionsofoptimumfocusandexposureandthetestconditions definedinthisInternationalStandard 3.18 ISOresolvingpower averagedmaximumresolvingpower,roundedaccordingtoTable5andISO497 NOTE ThereisanISOhigh-contrastandanISOlow-contrastresolvingpower. 4 Samplingandstorage Indeterminingtheresolving
36、powerofaproduct,itisimportantthatthesamplesevaluatedyieldtheaverageresults obtainedbyusers.Thiswillrequireevaluatingseveraldifferentbatchesperiodicallyundertheconditionsspecified inthisInternationalStandard. Priortoevaluation,thesamplesshallbestoredaccordingtothemanufacturersrecommendationsforalengt
37、hof timethatsimulatestheaverageageatwhichtheproductisnormallyused.Whennospecificrecommendationis made,storageshallcomplywiththespecificationsofISO554,23C 2Candarelativehumidityof(50 5)%. Severalindependentevaluationsshallbemadetoensurethepropercalibrationofequipmentandprocesses.The basicobjectiveins
38、electingandstoringsamplesasdescribedaboveistoensurethatthematerialcharacteristics arerepresentativeofthoseobtainedbyaconsumeratthetimeofuse. 5 Testmethod 5.1 Principle Theresolvingpowerofamaterialisdeterminedbyvisualinspectionoftheimageofthetribarresolving-power targetrecordedonthetestmaterialbymean
39、sofasuitablecamerasystem.Itdependsonthecontrastratio, polarityandexposure.Theresolvingpowerpassesthroughamaximumastheexposureischangedfromavalue atthetoeofthecharacteristiccurvetoavaluetowardtheshoulder.Furthermore,theresolvingpowerpasses throughamaximumasthefocussettingisgivensuccessivevaluesthatva
40、ryfromonesideofthecorrectfocusto theother. Inbrief,theprocedureistofirstdeterminetheexposurethatgivesthebest-resolvedimageofthetribarresolving- powertarget,usingthefocussettingdeterminedduringthecameraqualificationtest.Athroughfocusseriesis thenrunatthisexposureleveltooptimizefocus.Themaximumresolvi
41、ngpowerobtainedfromthisseriesisused todeterminetheISOresolvingpowerofasampleusingthescaledefinedinTable5. Becauseofthegranularstructureoftheimagewhenviewedundermagnification,areplicatesetoftenyieldsa rangeofresolvingpowervalues.Tomitigatetheeffectofthisvariable,ISOresolvingpowerisdefinedbelowin term
42、softhemedianvalueofasetofnotlessthanninereplicateimagesmadeatthesamefocusandexposure setting.ISO6328:2000(E) 4 Microscopicexaminationandreadoutofthetribartargetsimageisrequiredtodetermineresolvingpower.Since thetechniqueinvolvesobserverjudgmentindeterminingthefinestelementresolved,experiencehasshown
43、that, withoutapplicationoftheproceduresofthisInternationalStandard,observersmaydifferbymorethanafactorof twointheresolvingpowervaluetheyassigntothesameimage. NOTE Noknownsetofcalibratedimagesexistsfortraininganddefinitionpurposes. Accordingly,thisInternationalStandardprovidesasetofguidelinesthat,whe
44、napplied,hasbeenshownto produceconsistentresultswithinandbetweenobservers.Withtraininganduseoftheseguidelines,experienced observersshouldagreetowithin 1elementorabout 12%(intermsofcyclespermillimetre)forsingle-point estimates,and 6%formeanestimateswithastandarddeviationof 6%. 5.2 Apparatus 5.2.1 Ele
45、ment Theelementshallbethethreeparallelbarsandtwospacesofequalwidthandseparation,inscribedinasquareas showninFigure1.Foranegative-polaritytarget,theshadedpartofFigure1representsthedarkerportion,and theunshadedpartthelighterportion,ofthefieldofview.Thebarlengthtowidthaspectratioshallbe5:1.Interms ofdi
46、splacementL(perioddistanceinmillimetres)ofthebarsandinterspaces,thedimensionsofthesquareare 2,5Lx2,5L.TheshadedpartofFigure1istermedthe“surround“. ThewidthofthebarsandthewidthoftheinterspacesshowninFigure1shallbewithin 2,5%oftheaimvalue. Theoverallwidthandlengthoftheelement(2,5L)shallalsobewithin 2,
47、5%oftheaimvalue. Figure1Elementtestpattern Thespatialfrequency,expressedasreciprocalmillimetres,oftheelementmaybecalculatedbyoneofthe methodsdescribedina)orb)below.Selectionisbaseduponthemeasurementinstrumentationthatprovidesthe highestdimensionalaccuracywithinthedistancesbeingmeasured. a) Bymeasuri
48、ngthebarinterspacedistance,orperiodL,inmillimetres,andapplyingtheformula: Spatialfrequency= 1 L b) Bymeasuringtheoverallelementwidth(2,5L),inmillimetres,andapplyingtheformula: Spatialfrequency= 25, OverallelementwidthISO6328:2000(E)5 5.2.2 Tribarresolving-powertarget Thetribarresolving-powertargetsh
49、allbeanarrayofelementsasillustratedinFigure2. ThespatialfrequenciesoftheelementsinthearrayshallbeasshowninTable1.Thechangeinspatialfrequency betweensuccessiveelementsshallbeequalto 2010.Thiscorrespondstoincrementsofabout12%. Thetribarresolving-powertargetshallbeaspectrallynon-selectiveneutraltransparency. ThearrayofelementsinFigure2isapproximately100mmsquareandiscentredinasurroundthatisabout 125mmsquare.Thetwohorizontallinesare100mm 0,5mmapartandareusedtodeterminethemagnification. Theluminanceofthethreebarsofeachelementandtheluminanceofthesurroundshall
