BS ISO 6328-2000 Photography - Photographic materials - Determination of ISO resolving power《摄影 照像材料 ISO分辨率的测定》.pdf

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