正版教程-codev案例動(dòng)手做設(shè)計(jì)一個(gè)數(shù)碼相機(jī)鏡頭

Chapter t:DesignaDigitalCameraLens動(dòng)手做設(shè)計(jì)一個(gè)數(shù)碼相機(jī)鏡Inthischapter,youwilldesignafixed-focusdigitalcameralensforVGAres-).usetheNewLensWizardtoidentifyasuitablestartingpoint.根據(jù)說(shuō)明書(shū)的指導(dǎo)，你將會(huì)使用新鏡頭向?qū)ザx一個(gè)適宜的起點(diǎn)。Youwillthenmodify,yze,andoptimizetheopticalsystemtomeettherequirements.然后你將修改、分析、優(yōu)化你的光學(xué)系統(tǒng)使它滿足你的要求。ThiswillallowyoutolearnmostofthebasictechniquesneededtouseCODEV.這將使你學(xué)會(huì)使用CODEV的大部分基礎(chǔ)技術(shù)。ContentsLearningby TheNewLens CODEVIntroductoryUser’s Workingwith Chapter2Chapter2t:DesignaDigitalCameraLearningbyASimpleDigitalCameraLens一個(gè)簡(jiǎn)單的數(shù)碼相機(jī)鏡Digitalcamerasareverycommonthesedays,andthelatestmega-pixelmodelshave電子學(xué)。Butdon'tworrythatwon’tbeyourveryfirsttaskwithCODEV.但這并不你學(xué)習(xí)CODEV的第一任務(wù)。Insteadyouwilldesignafairlysimpleobjectivelensforafixed-focusdigitalcamera.你將為定焦數(shù)碼相機(jī)設(shè)計(jì)一個(gè)相對(duì)簡(jiǎn)單的物鏡。Thiswillstillrequiresomeopticaldesign,butit’sarelativelysimpleproblem,atwoorthree-elementcenteredlenswithglassand/orplasticrefractinglenselements.Hereiswhatyouwilllearninthischapter:以下將是你這章所要Interpretgeneraldesignspecificationsforasimplelens給出你的鏡頭的大致設(shè)Usethisinformationtoidentifyastartingpoint用這些信息來(lái)確定你的初Modifythestartingpointtomatchtherequirements修改你的設(shè)計(jì)初模使它符Performabasicysis,comparetheseresultswiththespecs,anddetermineguidelinesforoptimization執(zhí)行基礎(chǔ)分析，對(duì)比規(guī)格決定優(yōu)化指導(dǎo)Inthenextchapter,youwillusetheresultsofthischapterasastartingpointto下一 Optimizethelens優(yōu)化鏡 Identifyproblemswiththedesignforpotentialrefinement它和鏡頭細(xì)微改進(jìn)ThesestepswillallowyoutoworkwithmanyofCODEV'sfeaturesthroughvariousphasesofopticaldesign.在各個(gè)光學(xué)設(shè)計(jì)過(guò)程中將使你了解到CODEV里面的很additionalexplanationsinsubsequentchapters.在這章引入這些功能，并將DesignSpecifications設(shè)計(jì)說(shuō)SometimesyouwillreceivealensprescriptionfromsomeoneandyouwillneedtoenteritinCODEV,yzeit,andperhapsoptimizeit.Thisisfairlystraightforward.有時(shí)你將收到一些透鏡庫(kù)并把它載入CODEV，這是相當(dāng)簡(jiǎn)單Inothercases, adesignproblemstartsoutwithaspec,orsetofspecifications,onhowthelensmustperform,andfromtheseguidelinesyoumustdetermineastartingpoint,setitForthisdigitalcameraproblem,thespeccamefromaCODEVcustomerwhomakesconsumerproductsThequestionwas,“Ifyouwantedtodefinealow-cost,fixed-focusdigitalcameraforVGA,howwouldyouspecifyit?”對(duì)于一個(gè)數(shù)碼相Chapter2Chapter2Fixed-focusVGADigitalCameraObjective Smallnumberofelements(1-3)madefromcommonglassesorplastics由普Resolution分辨Pixelsize像素大 ObjectiveLens物Focallength焦距GeometricDistortion幾何畸變FSharpness銳

640x480effective7.4x7.43.55x4.74mm(fulldiagonal6Fixed,depthoffield750mm(2.5ft.)toinfinityFixed,6.0mmFixedaperture,MTFthroughfocus(centralareaisinner3mmofLowfreq.,17>90%>85%Highfreq.,51>30%>25% Cornerrelativeillumination>60%相對(duì)強(qiáng)Transmission透過(guò) Lensalone,>80%400-700IRfilterIR濾波 1mmthickSchottIR638orHoyaWhatDoesItAllForonething,thismeansthatitwillbearathersmalllenssystem.首先它意味著這是一個(gè)小型透鏡系統(tǒng)。Thesensorsizeandthefocallengthofthelensareeachonly6mm(aboutaquarterofaninch).尺寸和透鏡的焦距只有6mm。ThesensorsizeandtheeffectivefocallengthEFLwillestablishthefieldofviewFOV)forthelensaccordingtotheinfinite-object-distancerelationship,h=ftanèorImageheight=EFL*tan(semi-FOV)尺寸和有效焦距確定了無(wú)限遠(yuǎn)物的視場(chǎng)大小FOV，他們的關(guān)系是h=ftanè或ImageheightEFL*tan(semi-FOV)Inthiscasetheimageheightis3mm(halfofthedetectordiagonalandtheEFLis6mm,soyoucansolvethisforthesemi-FOVof26.5(thisisusefulsincethepatent

thatyouwantasmallnumberofelementsthisisalltheinformationyouneedtofindsomestartingpoints.考慮到想設(shè)計(jì)的是小單元，這就是你選取初模所需要的所有CODEVhasysisfeaturestoallowevaluationoftheotherspecs(distortion,thesefeatureslaterastheyareneededbutconsiderthetermsharpnessforamoment.SharpnessisoftendefinedbyMTF,whichfiesthelens'abilitytoimageinformationasafunctionofspatialfrequency.在它們需要的時(shí)候我們稍后將介紹以空間頻率函數(shù)的形式定量地描述了透鏡成像信息的能力。umsharpnessisgivenbyanMTFof1.0.Minimumsharpness(i.e.,noinformation)occursforanMTFof0.0.Highspatialfrequenciesrepresentsmalldetailsandaremeasuredinlinespermillimeter.WewilldiscussMTFandotherevaluationmethodsinmoredetaillater.當(dāng)MTF為1時(shí)銳度最大，當(dāng)MTF為0時(shí)銳度最小，高AdigitalcamerausesaCCDarrayconsistingofsmallbutfinite-sizedcellscalledpixels(thereareactuallythreecolorpixelsforeachcell,butfordesignpurposes,wewillthinkofeachcellasconsistingofasinglepixel).數(shù)碼相機(jī)使用CCD陣列成像，thepixelsizeis7.4micronssquare.Theumspatialfrequencythatthisarraywillresolvecanbecalculatedasoneovertwicethepixelsize,1/(2*0.0074)=67.6lines/mm.這些特性每個(gè)像素是7.4microns的方格，最大空間頻率可以通過(guò)陣列的尺寸算出1/(2*0.0074)=67.6lines/mmWiththisCCDarray,anyimageinformationwithahigherspatialfrequency(i.e.,finerdetail)thanthiswillnotbeseen.Inspiteofthis,theopticsmustactuallyhavenon-zeroMTFsomewhatbeyondtheCCDcutofffrequencysothecombinedoptics/detectorMTFwillproduceausablecontrastuptotheCCDcutofffrequency.高于這個(gè)空間頻率的圖像信息無(wú)法被所以MTF要綜合考慮CCD的截止頻率。ThisisthemeaningofthesmallChapter2Justt:DesignaDigitalCameraTheNewLensWizard新鏡頭向StartingaNewLens開(kāi)始設(shè)計(jì)一個(gè)新的鏡頭TheNewLensWizardisatoolforcreatingnewopticalsystemmodelsfromexistingdesigns(samples,patents,oryourownsavedfavori enses)orfromscratch.新鏡頭制作工具。Ithelpsyoutolocateasuitablestartingpointandthendefinetheessentialsystemd orrespondingtoyourspecifications(includingpupilsize, wavelengths,andfielddataStartCODEVandlaunchtheNewLensWizardnow:它根據(jù)你的設(shè)計(jì)要求幫ChoosetheFile .選擇FileNew菜ClicktheNextbuttonon escreen.點(diǎn)擊ClickthebuttonlabeledPatentLensandclicktheNextbutton.點(diǎn)擊PatentCODEVIntroductoryUser’s Chapter2Justt:DesignaDigitalCameraPatentDatabaseInadditiontosome30samplelensesthatdemonstrateprogramfeatures,CODEVincludesadatabaseofsome2,400expiredpatentsmainlycenteredopticalsystemsforvariousapplications).除了演示軟件特性的30個(gè)按列鏡頭外，CODEV還有2400個(gè)專利期滿的基（主要時(shí)各種光學(xué)系統(tǒng)的應(yīng)用技術(shù)）YoucanusetheNewLensWizardorthePatentLensSearchfeature(Tools>PatentLensSearch)toaccessandsearchthisdatabasethroughtheuseoffiltersthatspecifyvariousproperties.Inthefollowingprocedure,youwillcontinueusingtheNewLensWizardtoselectapatentlens.你可以用專利鏡頭搜索功能Tools>PatentLensSearch篩選符合要求的基本數(shù)據(jù)，接下來(lái)選擇一個(gè)專利鏡頭。IntheNewLensWizard,clicktheFilterbutton.在向?qū)е悬c(diǎn)擊TheFilterdialogboxdisplays,whichallowsyoutonarrowdownthesearchforastartingpoint.在Filter框中能縮小你的初模選擇范圍。Inthecaseofthedigitalcameralens,youneedbotharelativelyfast(small)f/numberandafairlywidefieldofvieworfieldangle(26.5semi-fieldangle,whichcorrespondstothe3mmhalf-diagonaloftheCCDarray).就數(shù)碼相機(jī)來(lái)說(shuō)，你對(duì)角線的CCD陣列）Youalsowantthislenstobefairlycheap,soitshouldhaveasmallnumberofelements(1-3).Youcanfillinthefilterdialogtostartthesearch.It'sagoodideatoexpandtherangeslightlysinceyoucanoftenslightlymodifyoroptimizeasystemtotheneededspecifications.你還想要你會(huì)還要修改和優(yōu)化它使它滿足你的要求。Ifyoumakethesearchtargetstoonarrow,youmaymisssomepromisingdesignforms.如果你的搜索范圍太窄ClickthecheckboxesandfillintheMin/Maxentriesfor點(diǎn)擊并填入一下信息F/#(f/number,try1to4),goalisFieldofView(actuallysemi-fieldangle,try20to33),goalisNumberofelements(try1to3),goalissmallestpossibleforlow ClickTheNewLensWizardreturnsyoutothepatentlistwhereyouwillnowfindaround12lensesthatmeettheserequirements.向?qū)⑹鼓慊氐綄，F(xiàn)Chapter2Justt:DesignaDigitalCameraYoucouldtryseveraldifferentstartingpoints,butnotethatitwillprobablybehardtoexpandthefieldofviewsowiderfieldstartingpointsarebetter.你可模會(huì)更好一些。Thelensnamedor02248lookspromising–ithasa27.5FOV,andafaster(smaller)f/numberthanweneed(2.4--thisisgood,sincestopdownalenstoalargerf/numberusuallyimprovesimagequality).一個(gè)名為or02248看上去不錯(cuò)27.5°FOV和afastersmaller)f/numberClickthelensnamedor02248inthespreadsheetofpatents.點(diǎn)擊專利表格中ClicktheNextbuttontogotothePupilpage.點(diǎn)擊DefiningtheSystemData確定系統(tǒng)數(shù)NowyoucancompletetheentryofthelensthroughtheNewLensWizard.Thenextfewscreensaskyouquestionsabouthowthelenswillbeused,propertiesthat上的一些問(wèn)題將問(wèn)你這個(gè)鏡頭是用來(lái)做什么的Notethatthegoalatthispointistogetaworkingmodelthatcanbemodifiedandoptimizedtomeetthefinalspecs.Furtherchangeswillbeneeded.注意到我們的目的是選一個(gè)我們能夠IntheNewLensWizard,youshouldbeonthePupilpage.ChooseImageF/Numberfromthedropdownlistandenterthevalue3.5.在向?qū)е泄馔?yè)面下拉列表中選擇ImageF/Number并填入3.5CODEVIntroductoryUser’s Chapter2Justt:DesignaDigitalCameraF/numberisaratiosoitwon’tneedtobescaledwhenthelensisscaledandthelenswillmostlikelyneedtobescaled).F/number是個(gè)比值，所以在縮放時(shí)你ClicktheNextbuttontogototheWavelengthpageandchangetheweightforthegreenwavelength(589.0)to2.點(diǎn)擊下一步進(jìn)入波長(zhǎng)頁(yè)面，并改變綠光（589nm）的權(quán)重至Thiswillgivethecentralwavelengthmoreemphasislaterinoptimization.這將ClicktheNextbuttontogototheReferencewavelengthpage,butdonotThisisthewavelengthusedforparaxialandreference-raytracingthedefaultisClicktheNextbuttontogototheFieldspage.Right-clickonfield2andchooseInsertfromtheshortcut toaddanadditionalfieldangle,thentypethevalues0,11,19,and26.5forthefourfieldYangles.點(diǎn)擊下一步Thislensisfairlywide-angleinfield,soaddinganadditionalintermediatefieldangleisagoodideaforoptimizationand practiceistohavefieldsdefinedat0,0.7andfullfieldataminimum.Addingintermediatefieldscanbehelpfulincontrollingzonalvariationoffielddependentaberrationssuchasastigmatism.最好的行為是在0，0.7和滿場(chǎng)情況 下，添加一個(gè)中等的場(chǎng)角對(duì)控制由散光之類的像差的場(chǎng)的變化是有幫助的ClicktheNextbuttontogotothelastpageintheNewLensWizard.點(diǎn)擊下一ClicktheDonebutton點(diǎn)擊完成Chapter2Justt:DesignaDigitalCameraWorkingwithSurfacesTheLensDataManagerSpreadsheet鏡頭數(shù)據(jù)管理表ThebasicoperationofCODEVisraytracing–everythingelseisbasedtosomeextentontracingoneormanyraysandngsomecalculationswiththem.Inthemajorityofsystems,raysaretracedsequentiallythroughaseriesofopticalsurfacesyouhavedefined.CODEV最基本的操作就是光線追蹤，其他的工作也是在光線統(tǒng)的大Thepropertiesofthesesurfaceswilldeterminehowtheraysaretraced.Thisiscombinedwithsystemdatatocreateamodeloftheopticalsystem.這些光學(xué)Sincesurfacesaretheheartofanyopticalmodel,youwillspendalotoftimelookingattheLensDataManager(LDM)spreadsheetwindow,whichisalwayspresentintheinterface(youcanresizeorminimizeitifyoudon'twanttoseeitbutyoucan'tcloseit).既然光學(xué)面是所有光學(xué)系統(tǒng)的，你將花很多時(shí)間用在鏡頭TheLDMwindowbehaveslikespreadsheetsinotherprogramsinthatyoucanresizerowsorcolumns,selectcellsorgroupsofcells,andenterdataincells.LDM就像Notethatsomecellsaregrayanddonotacceptdataentry—thesecellscontaindatacalculatedbytheprogramandthiscan'tbedirectlychanged.注意到一些單元格是canright-clickonanycell,includinggraycells,toseeaforthatcell.Rightclickingisaverycommonoperationwhichgivesquickaccesstoallavailableinformationforacell.你可以右擊任何一個(gè)單元格，包括灰色的單元格，并看到一個(gè)菜單。右擊是一個(gè)常用的操作，它可以快速使用單元格的可用信CODEVIntroductoryUser’s Tip:Toseethefullvalueofanydisplayednumber,positionthemousepointeroverthevalueleavethepointerthere(don'tclick).為了查看顯示數(shù)據(jù)值的全部，把鼠標(biāo)放在數(shù)值上就可以了。Tochangethenumberofdisplayeddigitsforallnumbersintheinterface,choosetheTools>CustomizeandgototheFormatCelltabintheCustomizedialogbox(Generalformatwith5digitsisusedinthisguide).Youcannotformatcellsindividually.要修改界面上數(shù)據(jù)值的顯示位數(shù)，選擇Tools>Customize進(jìn)入FormatCell在Customize框中修改就可以了，但你不可以Notealsothatinthediscussionbelow,weareconsideringthedefauisplayoftheLDMwindowforrotationallysymmetricoptics.Itispossibletohidecolumns(rightclickanyheadercell)ortomakecertaincommonentriesblank同時(shí)注意到下面討論藏豎欄或者把它們?cè)O(shè)成一個(gè)公共值(e.g.,SphereandRefract;choosetheTools>Preferences> andgototheUItabintheChapter2Justt:DesignaDigitalCameraPreferencesdialogboxtochangethis).Iftherearenon-rotationallysymmetricsurfacepropertiestheLDMwindowwilladdadditionalcolumnsforcertainXandYSurfaceEverylensmodelwillstartwithanobjectsurfaceandendwithanimagesurface(itisreallyjustthelastsurface,sincenoteverylensmodelwillformanimagethere,thoughmostwill).每個(gè)鏡頭模型都從物面開(kāi)始在像面結(jié)束（它事實(shí)上是最后一thatthereisalwaysasurfacelabeledStop,whichistheaperturestopsurfaceThisis孔徑光闌面，這是由軸上光線有限面所確定的。Thechiefrayorprincipalray)fromeveryfieldpointwillbeiteratedtopassthroughthecenter(x=0y=0ofthestopsurface,unlessyouoverridethisbehaviorwithchiefrayaiming(thisisonlynecessaryinafewunusualsituations).從各個(gè)場(chǎng)點(diǎn)發(fā)出的基線將重復(fù)經(jīng)過(guò)孔徑光EachrowintheLDMspreadsheethasasurfacenumberandasurfacename(optionalbutveryusefulincomplexsystems).Toselectanentiresurface(eachisdisplayedinarow)clickthesurfacenumberThesurfacetypeisnextwhichisadropdownlistdouble-clickittodisplayalistofsurfacetypes)withthedefaulttypeofSphere.LDM每行都有一個(gè)surfacenumber和一個(gè)surfacename,這是可選的面類型列表它的預(yù)設(shè)曲面類型是球面。TheYRadiusistheradiusofcurvature,whichisthereciprocalofcurvature.Spheresandotherrotationallysymmetricsurfaceshapeshaveonlyasinglecurvature,andYisusedforthis(typessuchasYToroidhaveXandYcurvatures).YRadius就是曲率半徑，它是曲率的倒數(shù)。球面和其他旋轉(zhuǎn)對(duì)稱曲面只有一個(gè)曲率。Youc sochoosetodisplaytheYCurvature(reciprocalofradius,e.g.,unitsof1/mm).Seethetipbelow.你還能顯示TipYoucanworkwithradiusofcurvatureoritsreciprocalcurvaturebycheckingorun-checkingtheEdit>RadiusMode item.你可以校驗(yàn)EditRadiusMode菜單選項(xiàng)來(lái)選擇是用曲率半徑模率模式ThicknessisdefinedasthedistancetothenextsurfacemeasuredalongthelocalZaxisofthecurrentsurface(whichistheopticalaxisforcenteredsystemssuchasthisNotethatthethickness(airspaceofsurface6isgrayandhasasmallSnextto角。Thisthicknessissetbyaparaxialimage(PIM)solve,whichcalculatesthe ChapterChapter2 t:DesignaDigitalCamerathicknessatwhichtheparaxialmarginalrayhasaheightofzeroatthesurface.這個(gè)厚度是由近軸成像得出的，通過(guò)計(jì)算邊界光線得出。Thissetstheparaxialimagedistance,wherethelensisapproximayinfocus.Thismaynotbethebestfocus,however,sothethicknessoftheimagesurfaceisusedasafocalshiftfromthePIMvalue(thetotalimagedistanceisthesumofthesetwovalues).這將設(shè)度的和）。Optimizationusuallydeterminesthebestfocusshift(thecombinationofPIMsolveandvariabledefocusis mendedformostopticalsystems).優(yōu)化通Glasscellscontainthenameofthematerialinthespacefollowingthesurfaceandifitisblank,thematerialisAIR.Theglassdeterminestheindexofrefraction,whichisafundamentalrequirementforraytracing.玻璃單元格包括曲面后填充空間它是光線追蹤的基本所需。Thereareseveralpossibleformsforglassnames,dependingonwhethertheyarefromglassmakers,definedlocallyforthelens(“privatecatalogordefinedasfictitiousglasswhoseindexcanbevariedtoallowoptimization,asshownintheexample(thereisadmacroglassfit.seqthatcanhelpyouconvertfictitiousglassesintorealglassesthatyoucanbuy).玻璃的名稱有很多種，它們的信息是有玻璃制造商提供的，你可Refractmodedeterminesthebasicbehaviorofasurface,whetherraysarerefractedorreflectedatthesurface(double-clickthecelltoseethechoices).Refractmode決ThefinalcolumnislabeledYSemi-Apertureandrepresentsthesizeoftheopticallyusefulportionofthelenssurface.Bydefault,thisisacentered,circularaperturecalculatedbytheprogramtopassthereferenceraysfromallfieldandzoompositions.最后一欄是YSemi-Aperture，它表示的尺寸是鏡頭表面非常有得出的。Youcanchangethistoauser-definedapertureforanysurfaceinseveralways,thesimplestofwhichistoright-clickandchooseoneoftheChangeto…optionsthatpopsup.Youcanjustacceptdefaultaperturesfornow,thoughlateryouwilllearnabouttherelationshipsbetweenapertures,pupilsize,andvignettingChangingand“Committing”ChangingdataintheLDMspreadsheetissimple—clickanon-graycellandtypeanewvalue.Youcsodouble-clickacelltodisplayandeditthefullvalue(orCODEVIntroductoryUser’s Chapter2Justt:DesignaDigitalCameradisplayalistofchoicesinsomecases).改變LDM表格的數(shù)據(jù)是很簡(jiǎn)單的，你只然后修改數(shù)據(jù)。Ifyouchangesomethingbymistake,usetheEdit>Undotofixit(makesurethataspreadsheetorcommandwindowisinfront;Undowillnotbeavailableifagraphicswindowordialogboxisinfront).如果你修改時(shí)修改錯(cuò)了可以用EditUndo來(lái)取消你之（但必須保證數(shù)據(jù)表或指令窗口是開(kāi)著的，否則它將無(wú)法使用）Notethatsomecellshaveasmallsymbolor“glyph”nexttothevalue,identifyingaspecialstateforthatcelle.g.,Sforsolve,VforTochangethestateofanycell(includingagraycell),right-clickonittoseeashortcutofoptions(e.g.,changingasolvetoavariablewillremovethesolveandallowyoutochangethevaluedirectlybutbesureyouwanttodothissincethesolvemaybethereforareason).要改變單元格（包括灰色的）的狀態(tài)右擊它會(huì)看Oneoftheright-clickchoicesonanysurfacedataitemwillbeSurfaceProperties.ThisopensalargewindowthatgivesdirectaccesstoALLpropertiesofthatsurfaceincludingmanythatdonotappearintheLDMspreadsheetWewillcoverSurfacePropertiesalittlelater.每一個(gè)單元格右擊菜單選項(xiàng)中都有個(gè)YoucsochangedataintheLDMspreadsheetbytyappropriatecommandsattheCODEV>promptintheCommandWindow.Thisrequiresknowingtheapplicablecommandanditssyntaxe.g.THIS52.3willchangethethicknessof你知道相關(guān)指令和語(yǔ)法。WhenyouenteracommandthiswayandpresstheEnterkey,youwillalsoseethecorrespondingLDMspreadsheetorSurfacePropertiesDon’tFearCommitmentInCODEV,weusetheterm“commitchanges”torefertotransferringthedatafromtheplaceitisenteredintheuserinterface(suchasaspreadsheetcellordialogbox)tothelensdatabaseinsideCODEV(sometimescalledthe“backend”ofCODEV).Normallydataiscommittedinstantly—thatis,assoonasyoutypeorclickinanothercelldatafieldorwindow.在CODEV里面，我們采用“修改責(zé)任書(shū)”的的修改數(shù)據(jù)了。ThisissimilartootherprogramssuchasExcel,exceptyouwillalsoseethecorrespondingcommandsdisplayedintheCommandWindow.這點(diǎn)和Excel However,therearesomecasesinwhichacommandisbuiltfromseveraldatavaluesenteredinarowofasmallerspreadsheet(e.g.,aperturesintheSurfacePropertieswindow)InthiscasethenumbersarenotcommitteduntiltherowisThethingthatmaybeconfusinghastodowiththedifferenttypesofwindows.WindowsinCODEVcomeintwobasictypes,thosethathaveOKandCancelbuttons(thesearecalleddialogboxes),andthosethatdonot(themainexamplesbeingtheSurfacePropertiesandSystemDatawindows).當(dāng)遇到不同窗口時(shí)是一件讓人容易的事CODEV窗口有兩種類型一種是框它們都有OKandCancel按鈕，另一類就沒(méi)有這兩個(gè)按鈕了，如SurfacePropertiesandSystemDatawindowsDialogboxeswithOKbuttons(includingthedialogboxesforCODEVoptionssuchasMTF)donotcommitanythingtothebackenduntilyouclickOK.IfyouclickCancel,nochangesareactuallymade.框里的OK按鈕點(diǎn)擊后操作就生效了，點(diǎn)擊取消那么你剛才的修改就不生效。InthecaseoftheSurfacePropertiesandSystemDatawindows(andafewothers,allassociatedwiththeLDM)youcankeepthemopenwhileyouworkinotherwindows,orclosethembyclickingtheXintheupperright-handcornerofthewindow.曲面性質(zhì)窗口等其他窗口在操作其他窗口時(shí)可以打開(kāi)也可以點(diǎn)擊它右上角的X關(guān)掉它。Changesmadeinthesewindowsarecommittedimmediay,justliketheLDMspreadsheet;however,youcanbesuredataiscommittedtothelensdatabasebyclickingtheCommitChangesbutton.YoucanseewhatdatahasbeencommittedintheCommandWindow,whichdisplaysthecommandsgeneratedforthese是在點(diǎn)擊CommitChanges后生效的，你可以在指令窗口中查看你的操作指Don'tworrytoomuchaboutthis—youcwaysuseUndotogetbacktoanyearlierstateofthelensincaseyouchangesomethingyoudidnotintendIt'salsoagoodideatosaveyourlensinafilewheneveryoumakesignificantchanges(File>DrawingPicturesNowyoucanunderstandtheLDMspreadsheetbutastheysayapictureisworthathousandnumbers.Soit'sagoodideatodrawapictureofthelensassoonasyoucanManyproblemsareeasytospotonalenspictureThereareanumberofwaystodrawlenses,includingtheveryflexibleVIEWoption(Display>ViewLens),butfornow,there'saquickerway.現(xiàn)在你已理解LDM列表了是一幅圖比一千我們有很多種方法來(lái)繪圖，包括Display>ViewLens菜單，但現(xiàn)在我們有一種Chapter2Justt:DesignaDigitalCameraClicktheQuick2DLabelediconontheIt’sthemiddleonethatshowsalensandapencilalongwiththeletterQ(forquick)andtheletterL(forlabeled—floatthemouseoverittoseethetool-tiphelptosee2D–Labeled”）Keeptheresultingwindowopenasyouwork(resizeandmovethewindowasdesired).Whenyouchangesomething,clickthe“execute”buttonintheupperleftcornerofthewindowtoredrawthelenspicture.在你工作時(shí)一直開(kāi)著效果 yzingthislens,youwillmorethanlikelyneedtoscaleittotherequiredeffectivefocallengthEFL).在分析這個(gè)透鏡前更可能需要將它縮放到所需的SurfaceOperations:ScaletheLensAlthoughyousetthef/numberandfieldanglestothedesiredvaluesintheNewLensWizard,youneedtobesurethelenshasthespecifiedeffectivefocallength(EFL)of6mm.OnewaytodeterminethisistodisplayawindowoffirstorderCODEVIntroductoryUser’s Chapter2Chapter2t:DesignaDigitalCameraChoosetheDisplay>ListLensData>FirstOrderData,andre-size/re-positiontheresultingwindowforconvenientviewing.NotethevaluelabeledEFLinthiswindow(0.9528mm).Thisiswrongforapplication,andscalingthelensdataisthenormalwaytofixthis.選擇Display>ListLensData>FirstOrderData菜單，并把它調(diào)整到合適的Tip:YoucanplacetheEFLandvariousotherlenspropertiesonthestatusbaratbottomofthemainCODEVworkspace.Thisallowscontinuousmonitoringoftheseitems.ChoosetheTools>CustomizeandclickontheStatusBartabintheCustomizedialogboxtoaccessthisfeature.你可以把EFL等其他各種鏡頭的性質(zhì)選擇Tools>Customize再點(diǎn)擊StatusBar,你將在框中進(jìn)入這些功能。Selectsurfaces1toImageintheLDMspreadsheetwindow(clickinthesurfacecolumnanddragtoImagetoselecttherange).在LDM窗口中選中曲面1到像（點(diǎn)擊surface#列并拖到像來(lái)選擇它們）ChoosetheEdit>Scale todisplayadialogboxnotethatthesurfacerangeissetto1toImage).點(diǎn)擊Edit>Scale菜單出現(xiàn)一個(gè)框（注意曲面范圍是從1到像）ClickthebuttonlabeledScaleEffectiveFocalLength,thenenterthevalue6.0inthefieldlabeledScaleValue.點(diǎn)擊ScaleEffectiveFocalLength這個(gè)按鈕，然后在ScaleValue這個(gè) Chapter2Justt:DesignaDigitalCameraClickOKtoscaletheClicktherecalculatebutton intheListFirstOrderDatawindowtoupdateit.在ListFirstOrderData窗口中點(diǎn)擊重新計(jì)算來(lái)更新它。NotethattheEFLvalueisnow6mmasdesired.Notealsothattheparaxialimageheightis2.99mm(closeenoughtothedesired3mm).你會(huì)發(fā)現(xiàn)EFLClicktheRecalculatebuttonintheQuick2DLabeledPlotwindowtoupdatethepictureasshownbelow.在Quick2DLabeledPlot窗口中重新計(jì)算，會(huì)更CODEVIntroductoryUser’s Chapter2Chapter2t:DesignaDigitalCameraNewTitleandStarting“SaveSofarsogoodbutbeforecontinuingyoushouldlabelandpreservetheworkyouhavedoneuptonow.Notingthatthisisanexpiredpatentwhichisabouttobechangedbyoptimization,youcansetanewlenstitleandsavethisasastartingpoint.ChoosetheLens>SystemData andclickSystemSettingsintheSystemDatawindow’snavigationtree.選擇LensSystemData菜單，并在系統(tǒng)數(shù)據(jù)導(dǎo)航樹(shù)中點(diǎn)擊SystemSettingsSystemDataiswheremostnon-surface-relateddanbeviewedandmodified.ThebasicSystemDatavalues(pupil,wavelengths,field)weredefinedintheNewLensWizardbutyoucanviewandchangethesepropertiesandmanyothersthroughtheSystemDatadialogbox.系統(tǒng)數(shù)據(jù)是大部分無(wú)相在新鏡頭向?qū)е卸x的，但卻能在系統(tǒng)數(shù)據(jù)框中查看和修改這些性 SelecttheTitlefieldandchangeittosomethinglikeDig.Cam.VGA:start(youhaveupto80characters,butdon'tincludeanyquotesorapostrophes).TabtoorclickinanotherfieldtocommitthisdatatotheCODEVlensdatabase.選擇Title處并把它改成類似DigCam.VGAstart的名字（你可ChoosetheFile>SaveLensAs andenterafilenamesuchasDigCamStart.len,thenclickSave.選擇File>SaveLensAs菜單并 ChapterChapter2 t:DesignaDigitalCamerayzetheStartingTherearemanytypesofysisinCODEV,butonlyafewofthemareneededtodetermineifyouaremeetingthespecs.Theresultsoftheseyseswillalsoguidethesetupforoptimization(ifrequired):在CODEV里面有很多種方法來(lái)實(shí)現(xiàn)分析Firstorderrequirements(doneafterscalingthelens,asdetailedin“SurfaceOperations:ScaletheLens”onpage29;thescaledlenshasthecorrectfirst-orderfocallengthandimageheight)一階性質(zhì)的要求（你已完成了29頁(yè)那Distortion(FieldCurvesand/orDistortionGrid)畸變（場(chǎng)曲率和畸變柵格Sharpness(diffractionMTF—thiswillalsoestablishdepthoffocus,byyzingMTFwithadifferentobjectdistance)銳度（衍射MTF，這 Inaddition,youwillalsouseacoupleofquickysisfeaturesforreference(spotdiagramandrayaberrationcurves).同時(shí)你將使用一些快速分析功能作為參考（斑點(diǎn)圖和光線像差曲線）WewillexplainthebasicsoftheseysisoptionsnowAdditionalinformationwillbeprovidedinalatersectionofthisguidethatcoversevaluationfeatures.Thereisonemorethingthatneedstobedonewiththestartingpoint,thoughitdoesnotneatlyfitintoanyspecificysiscategory:ghatomonelevenuallymnufacurehislns,therearecrtanpracialissue.eheeemntstomallortolgeomakeey?ethytoohinortohickforpraccalfaricaion?Cnhybeassmbldndmountdeasl?Isheglassvailble,ndisitexpnsve?Thesereebascquon,ustbenswerdnthebassoflokingatthebclesdaandgtoeneuyeooesdperhpsakomoneohsdesgndruiltaropti.（CODEVIntroductoryUser’s Chapter2Chapter2t:DesignaDigitalCamera題，也可以問(wèn)一下有經(jīng)驗(yàn)的人Thereareotherfeasibilityissuesthataremoretechnicallycomplex.Oneis ysis,whichwillbeintroducedlaterinthisguide.還有其他復(fù)雜的技tohowaccuraytheelementsmustbefabricatedandmountedtomaintainarequiredlevelofperformance.Anotherthatwon'tbecoveredisthermalysis(althoughCODEVcanhelpwithsomeaspectsofthis,suchaschangesinperformanceduetoasimpletemperaturechange).這將關(guān)系到這些部件實(shí)際上是QuickRayAberrationCurveArayaberrationcurveisausefulwayoflookingatraytracedatatoseepatternsthatmaycauseproblems.光線像差曲線是一個(gè)查看光線追蹤數(shù)據(jù)的非常有用的方法，它能從圖中看出一些問(wèn)題。Transverserayaberrationsaremeasuredontheimagesurfaceasthedistancefromaparticularraytothechiefrayforthesamefieldpoint(foraperfectlensthisshouldbezeroforeveryraytracedfromthesamefieldpoint).Thisisplottedasafunctionofpositioninthestoporpupilforalineofevenlyspacedrays(arayfan).橫向光線像差是在像面上同一場(chǎng)點(diǎn)的一條特殊光Youarefirstlookingforlargedeviations,includingseparationsbetweenthecurvesfor.同波長(zhǎng)曲線間的偏離（色差）Youmayalsolookfordistinctivepatternsthatrepresentcoma,astigmatism,andotherbasicaberrations.你也會(huì)看到其他像差的特征圖像，如慧差、散光以及其他基本像差。Experiencecanlyouwheresuchaberrationscomefromsuggestingwhereyoumightmakecorrections,perhapsintheformofadditionalelementsoraspheres.經(jīng)驗(yàn)?zāi)芨嬖V你這些像差來(lái)自哪些因素，TheQuickRayAberrationplotisaone-clickversion,whichyourunbyclickingtheQuickRayAberrationplottoolbarbutton,shownbelow(forthegeneralcase,choosetheysis>Diagnostics>RayAberrationCurves,optionname:RIM,for“rimray”).在中點(diǎn)擊QuickRayAberrationplot就會(huì)得到快速 單，選項(xiàng)名RIM意為rimray）TheQuickversionisactuallydonebyamacroandperformsautomaticscaling(italsosatexttableofrayaberrations,generatedbytheANAoption).NotethatthefollowinggraphisshownafterzoomingandpositioningonlythehighestfieldangleintheQuickRayAberrationPlotwindow.Thestartingpointdoesn'tshowsignsofanygrossaberrations,thoughyoucanonlylthisbylookingatthescaleandknowingwhatisbig.Theautomaticscalevaluehereis0.023mm,23microns.Forcomparison,theAirydiskdiameter(diffractionspotsizeforaperfectlens)is2.44*(wavelength)*(f/number),orabout0.004mmforf/3.5Thislensisnotdiffractionlimited(norwouldyouexpectittobebutitsaberrationsarewithinafactorof6oftheAirysize.初模不會(huì)告訴你像差的征兆你可以通過(guò)查看圖像數(shù)據(jù)Tip:Alwaysusethegraphicalzoomtooltozoominonthescalenumbers