单反镜头的基本知识

清水混凝土的配合比设计中，要针对当地水泥、砂石、外掺料及外加剂等原材料影响混凝土质量的多种因素进行分析，确定主要控制因素，并从经济性和使用要求综合考虑，优选出符合生产条件的最优方案组合。obstacles,correctingmisunderstandings,advocategoodcadrestyle.2,adheretothescientificdecision-makinganddemocraticdecision-makingdecision-makinglaw.Correctlyhandletoensurethatgovernmentdecreesandbasedontheactualcreativework,givingfullplaytosubjectiveinitiative,putanendtoimplementtheconferencemeeting,todocumenttheimplementationofdocumentsetc.Improvethescientificanddemocraticdecision-makingmechanism,improveandimplementthedecisiontosolicittheviewsofexperts,thepublichearingsystem.Improvetheimportantdecisionofriskassessmentmechanismandlegalreviewmechanism.3,topromoteteamunity.Upholdandimprovethesystemofannualpartybooktalkhearttoheart,mindandPartymembers,Partymemberstoexchangeeachothernotlessthan2times.Theimplementationofsoundteamdemocraticlifesystem,consolidateandenhancetheparty'smasslineeducationalpracticewillpromotetheachievementofthetopicofdemocraticlife,criticismandself-criticismnormalization,along-term.Adheretothepartyonthebasisoftheprincipleofunity,enhanceinternalcommunication,strengtheninternalsupervision,selfSleepmaintenanceteamcollectiveimageandauthority.(three)toensuretheexecutionisnotstrongordisguisedtoresistgovernmentdecreesissues.IndividualBureauleadershipteammemberslackoflearningpoliticaltheorysystem,notfromtheobjectivereality,notwiththeparty'sinterestsabovealltheprinciplestodealwithpersonalproblems.Inthespecificworksafetysupervisionintheexecutionisnotstrong,intheimplementationofthedecisiontodeploythediscount,makechoices,engageinwork,theimplementationoftheagreement,uncomfortableisnotperformed,openordisguisedtoresist,thelackofsubjectconsciousnessofthepartyorganization,thelackofresistinsocietyallkindsofbadhabitsandunwholesometendenciesofcourageGasandcourage.Suchastheliabilityinsuranceofsafeproductionwork,individualleadersthathavesomeonearrested,andnofunding,notintheglobalchessperspectivetothecountrysidetocarryoutdailyinspection,foundnoneofmybusinessacceptanceoftheresumptionofproductioninanarmchair,withapen,indifferent.Correctivemeasures:(LEDLeadership:LuoMingjun,rectificationtime:beforeSeptember25th,insistforalongtime)1,tostrengthenthesenseofresponsibility,worktosolvethelackofdecentoccupationexplainaway,conductproblems.Toestablishtheoverallconcept,eliminatedepartmentalism.Strictassessmentandaccountability,tosolvethespiritualslack,nianqingpazhong,statusquo,Toestablishandperfectthemuddlealongandotherissues.Bureaustaffconductworkregulations,standardizethebehaviorofpersonnel.2,strengthentheresponsibilitysystem.Oneisthein-depthstudyandimplementtheHunanprovincialPartyandgovernmentleadingcadresInterimProvisionsontheworksafetyofapairof(HunanOfficeissued2013No.单反镜头的基本知识不论是应用于传统胶片单反相机的镜头，还是日渐流行的数码单反相机专用镜头，其镜头标识的文字中，都基本包含了镜头属性、焦距参数、光圈参数、所具特点等信息。详细地说上列四点可以归纳为：镜头属性：通常表示该镜头是AF卡口还是EF卡口，通常还包括一些镜头类别的标识；焦距参数：表示镜头的焦距范围，单位为mm；光圈参数：表示镜头的最大光圈系数，有些镜头还标识出镜头的最小光圈系数；所具特点：表示镜头所采用的特色技术等；这也是后文中重点解释的内容。这些信息通常的表现方式如“CANONZOOMLENSEF-S10-22mm1：3.5-4.5USM”。根据这些信息，使我们判读出这款镜头的完整参数：佳能原厂EF-S电子卡口自动变焦镜头；焦距范围10-22mm（超广角2倍变焦）；最大光圈系数3.5-4.5；采用了USM超声波马达。另外，版本序号也是常见的标识文字内容之一，它表示该镜头在同规格镜头中，主要表述其属于第几代产品。==================================================不同镜头，最先让人去认识的必定是它的焦段，如何辨别和认识不同焦段的常用范围，是最基本、最需要去掌握的知识。焦段介绍：10mm左右的焦段，是超广角焦段。主要用于风景摄影，纪实摄影等，照出来的角度非常大，很有冲击力。24mm左右的焦段，是小广角，主要用于风景摄影，纪实摄影等，旅游纪念照用这个焦段不错。50mm左右的焦段，是标准焦段，视角平易近人，变形少，主要用于风景摄影，人像摄影，纪实摄影等。85mm左右的焦段，是中焦段，这个焦段主要用于拍人像，静物等。200mm左右的焦段，是长焦段，这个焦段常用于抓拍，特写等。500mm左右的焦段，是超长焦段，这个焦段就可以打鸟了，也就是拍鸟。500mm以上的超长焦，打鸟更方便，隔一个操场远偷拍很轻松。长焦，超长焦还经常被用在体育摄影。总结发言：镜头上通常有几个数据：焦距(段)\光圈\最近对焦点（PS：现在很多都没有这个参数）比如说：某镜头参数为“18-50mmF2.8-3.50.5m-∝”。就是说，这个镜头的焦段是18-50mm，在18mm广角端的最大光圈是2.8，在50mm最大光圈是3.5，最近的对焦点(广清水混凝土的配合比设计中，要针对当地水泥、砂石、外掺料及外加剂等原材料影响混凝土质量的多种因素进行分析，确定主要控制因素，并从经济性和使用要求综合考虑，优选出符合生产条件的最优方案组合。obstacles,correctingmisunderstandings,advocategoodcadrestyle.2,adheretothescientificdecision-makinganddemocraticdecision-makingdecision-makinglaw.Correctlyhandletoensurethatgovernmentdecreesandbasedontheactualcreativework,givingfullplaytosubjectiveinitiative,putanendtoimplementtheconferencemeeting,todocumenttheimplementationofdocumentsetc.Improvethescientificanddemocraticdecision-makingmechanism,improveandimplementthedecisiontosolicittheviewsofexperts,thepublichearingsystem.Improvetheimportantdecisionofriskassessmentmechanismandlegalreviewmechanism.3,topromoteteamunity.Upholdandimprovethesystemofannualpartybooktalkhearttoheart,mindandPartymembers,Partymemberstoexchangeeachothernotlessthan2times.Theimplementationofsoundteamdemocraticlifesystem,consolidateandenhancetheparty'smasslineeducationalpracticewillpromotetheachievementofthetopicofdemocraticlife,criticismandself-criticismnormalization,along-term.Adheretothepartyonthebasisoftheprincipleofunity,enhanceinternalcommunication,strengtheninternalsupervision,selfSleepmaintenanceteamcollectiveimageandauthority.(three)toensuretheexecutionisnotstrongordisguisedtoresistgovernmentdecreesissues.IndividualBureauleadershipteammemberslackoflearningpoliticaltheorysystem,notfromtheobjectivereality,notwiththepart