1.0 Introduction
With the rapid development of globalization, cultural communication is getting more and more necessary and frequent. English, as one of the most popular languages, is playing a more and more significant role in communication. At present, English acquisition is commonly required, therefore, the role of English teacher is very important. Traditional English teaching follows teacher-centered principle, attaching more importance to the subject knowledge instead of students’ ability of language using; emphasizing teacher’s importance instead of students’. Thus, students gradually and greatly depend on teachers, their desire and ability of learning are lowered. They can deal with all kinds of written examinations, but can’t communicate freely in English. They are successful in acquiring language system as a separate body of knowledge but fail to learn how to use it. The limits of traditional teaching are more and more obvious and criticized by many researchers (Xu Enmei, 2002; Lu Yun, 2004; Chen Wencun, 2007).
Since the traditional teaching approach couldn’t meet the requirement of English teaching, new approach is needed. Therefore, it’s time for English teachers to adopt a new theory and change their roles in English teaching. Task-based Language Teaching (TBLT) follows this trend and comes into being. Compared with traditional teaching approach, TBLT insists that language learners develop the language ability by using language. It provides a circumstance for students to build up their confidence, cultivate a good learning habit, develop their self-study ability and form effective study strategies. Thus, the aim of English teaching can be achieved.
This paper consists of five parts. Chapter one is introduction. It introduces the current situation of Chinese English teaching, significance and organization of this paper. The second chapter is literature review. It introduces the theory of TBLT, especially the definition of “task”, and gives a brief introduction of the concept of teacher’s role in EFL (English as Foreign Language) teaching and the reasons that TBLT can be adopted in English teaching. The third chapter is the detail illustration of teacher’s role s in TBET. The limits of traditional teaching and the reasons of changing teacher’s role s are also given. The fourth chapter is suggestions for Chinese English teachers. The author gives some suggestions to Chinese English teachers, emphasizing the importance of changing teacher’s view, analyzing and developing curriculum
resources, teaching according to reality and self-development. The last part is the conclusion of this paper.
2.0 Literature Review
2.1 The Concept of T eacher’s role in EFL Teaching
Ellis and Mcclintock defines “role”as the part taken by a participant in any act of communication (Huang Shuyun, 2004). Jack Croft Richards states that when roles are compared, they have the following characteristics:
a. They involve different kinds of work and different levels of responsibility,
b. They involve different kinds of relationships and different patterns of interaction and communication,
c. They involve different power relationships (Huang Shuyun, 2004).
The concept of “role” in E FL teaching denotes the function that teacher and learners perform during the course of a lesson, therefore, English teacher’s role means the function that teacher performs during an English lesson. As students’ needs and le sson objectives are different, teacher has to take many different roles in English teaching.
Harmer has identified English teacher’s roles in hi s work: as controller in eliciting nationality words; as assessor of accuracy as students try to pronounce the words; as corrector of pronunciation; as organizer in giving instructions for the pair work, initiating it, monitoring it, and organizing feedback; as prompter while students are working together; and as resource providers if students need help with words and structures during the pair work (Xu Enmei, 2002).
2.2 Definitions of Task
A Course in English Language Teaching(Wang Qiang, 2006) provides a number of definitions of task from both the research and pedagogic literatures. The listed definitions are from this book.
Long defines “task” as a piece of work undertaken for oneself or for others, freely or for some reward. Thus, examples of tasks include painting a fence, dressing a child, filling out a form, buying a pair of shoes, making an airline reservation, borrowing a library book, taking a
driving test, typing a letter, weighing a patient, sorting letters, taking a hotel reservation, writing a cheque, finding a street destination and helping someone cross a road. In other words, “task”means the hundred things people do in everyday life, at work, at play, and in between.
Breen states that “task” refers to any structured language learning endeavor which has a particular objective, appropriate content, a specified working procedure, and a range of outcomes for those who undertake the task. “Task” is therefore assumed to refer to a range of work plans which have the overall purpose of facilitating language learning — from the simple and brief exercise type, to more complex and lengthy activities such as group problem-solving or simulations and decision making.
Prabhu defines task as an activity which requires learners to arrive at an outcome from given information through some process of thought, and which allows teachers to control and regulate that process.
Nunan defines “task”as a piece of classroom work which involves learners in comprehending, manipulating, producing or interacting in the target language while their attention is principally focused on meaning rather than form.
Willis defines “task” as an activity where the target language is used by the learner for a communicative purpose (goal) in order to achieve an outcome.
Ur states that “task” is essentially goal-oriented; it requires the group, or pair, to achieve an objective that is usually expressed by an observable result, such as brief notes or lists, rearrangement of jumbled items, a drawing, a spoken summary. This result should be attainable only by interaction between participants, therefore, within the definition of the task you often find instructions such as “reach a consensus”, or “find out everyone’s opinions”.
Skehan defines “task”as an activity in which meaning is primary, there is some communicative problem to solve; there is some sort of relationship to the real world; task completion has some priority; and the assessment of task performance is in terms of task outcome.
Bygate, Skehan and Swain define “task”as an activity which requires learners to use language, with emphasis on meaning, to attain an object.
Ellis defines “task” as activity that call for primarily meaning-focused language use.
The above definitions present many dimensions of a task, such as the scope of a task, the perspective from which a task is viewed, the authenticity of a task and the outcome of a task.
Although there are so many definitions to task, since the present study focuses on language teaching, therefore, classroom tasks should consist of the following points: a.meaning-centered. Tasks should be designed to practice some meaningful language forms; b. the aim of a task is to solve certain communicative problem, which should have some connections with the real world.
A good task is close to students’ real life, learning experiences an d social reality, and could arise students’ interests and encourage students’ participation in the task; c. the design of the task must emphasize the importance of task completion, that is, the settlement of the communicative problem. The result of the task is the criteria of the success of the task.
2.3 Definitions and Features of TBLT
TBLT is a further development of communicative language teaching. Communicative approaches became popular in the 1970s. In 1987, Yalden summarized that there were five approaches in communicative approaches: functional approach, negotiated approach, natural approach, content-based approach, and task-based approach. Therefore, task-based approach is the latest development in communicative approaches. TBLT shares the same belief with communicative language teaching that language should be learned as close as possible to how it is used in real life. The difference is that it stresses the importance of combining form-focused teaching with communicative-focused teaching. TBLT sees language as a resource for communicating rather than as a body of content to be memorized. The aim of learning a foreign or second language is to achieve communicative competence. It is the pedagogy that best fits the principle of “learning by doing”.
Skehan claims that TBLT may underlie language systems which can be formed and developed well while learners focus on the process of doing tasks (Ren Yankun, 2006).
Chen Lin, Wang Qiang and Cheng Xiaotang (2002:1) state that during TBLT, the task itself is the motivation of learning, the process of completing the task is the learning process, the results of teaching and learning are presented in the task achievements. With the concrete motivation, students will learn autonomously and use the language they are learning to do things actively. They will use the language they are learning naturally while doing things, and
then develop their language competence in the process of using the language to do things.
Willis (1996) illustrates the framework of TBLT, consisting of three phases: pre-task, task-cycle and language-focus. The following is a list of TBLT.
Pre-task: to introduce the class the topic of the task, activating topic-related words and phrases.
Task-cycle: to offer learners the chance to use whatever language they already know in order to carry out the task, and then to improve that language under the teacher’s guidance while planning their reports of the task. It is divided into three steps: task (students carry out the task), planning (each group prepares how to report their completion of the task to the class) and report (students report their completion of the task).
Language-focus: to allow a closer study of some of the specific features naturally occurring in the language used during the task cycle. The students analyze and assess the completions of tasks by other groups. And they practice the language difficulties under the direction of the teacher.
In this paper, the author analyzes English teacher’s roles in TBLT according to Willis’s definition of TBLT.
To understand TBLT, it’s better to get familiar with its features. TBLT has the following features:
a. TBLT is objective-oriented, i.e. learners work purposefully towards an objective,
b. TBLT does not oppose the teaching of grammar, because the objective of TBLT can be language-focused, i.e. to discover rules of grammar,
c. In TBLT classroom, learners’ attention is principally focused on meaning rather than on form, i.e. for most of the time, their attention is on what is being expressed,
d. Communication tasks bear resemblance to activities people carry out in everyday life,
e. Tasks are often carried out in cooperation with others,
f. Outcome is important to assess the effect of TBLT,
g. The outcome may be something concrete, (i.e. a timetable, a report) or something intangible
(e.g. agreement or solution to a problem) (Tian Jinping, 2006).
2.4 Theoretical Basis of TBLT
Language learning is basically considered as a cognitive process of the input and output of the information. Therefore, this paper illustrates the theoretical basis of TBLT from the perspective of cognitive approach, input hypothesis, output hypothesis and interaction hypothesis.
Cognitive approach is based on the distinction in the way in which students represent knowledge. Students construct both an exemplar-based system and a rule-based system. The former is lexical in nature and includes both discrete lexical items and ready-made formulaic chunks of language. The latter consists of abstract underlying patterns of the language. They are needed when students have to construct utterances to express precisely and properly. In TBLT, the process of completing tasks offer opportunities for students to construct the two systems.
Krashen is the representative of input hypothesis. In 1981, Krashen declares that we acquire language in only one way, which is by receiving comprehensible input. If the input contains forms and structures just beyond the learner’s current level of competenc e in the language, then comprehension and acquisition will occur. This hypothesis was later modified and it held that learners also need the right environment and circumstances to allow comprehensible input to work. They have to be motivated and free of stress. Based on this hypothesis, TBLT advocates that tasks should be relevant to students’ life and interests and should be carried out in a comprehensible language.
The output hypothesis emphasizes that production opportunities are the key formative process for acquisition, and acquisition can be enhanced in context in which learners are pushed to convey messages precisely. Swain is the representative of output hypothesis. He contends that output results from interactive language tasks as they provide learners with opportunities for contextualized, meaningful language use. Such opportunities enable learners to test the target language and move from a semantic analysis of the language to a syntactic analysis of it. Therefore, TBLT emphasizes the importance of meaningful and interactive tasks (He Lili, 2006).
Seliger is the representative of interaction hypothesis. After many researches on the relationship between interaction and acquisition, Seliger concludes that learners who initiate interaction are better able to turn input into intake. Therefore, it’s necessary to change students’
passive learning to active learning. TBLT meets this requirement and follows students-centered principle (He Lili, 2006).
2.5 Principles of TBLT
TBLT follows students-centered principle. Ellis states principles of TBLT in detail:
a. ensure an appropriate level of task difficulty,
b. establish clear goals for each task-based lesson,
c. ensure that students adopt an active role in task-based lessons,
d. encourage students to take risks,
e. ensure that students primarily focuse on meaning when they perform a task,
f. require students to evaluate their performance and progress (Chen Wenchun, Yan Ping, Yu Meigen and Peng Kangzhou, 2007).
2.6 Reasons that TBLT can be Adopted in English Teaching
Why can TBLT be adopted in English teaching? To put it simply, it follows the present view of language learning.
Traditionally, it is held that learning a language involves mastering the building blocks of the language and learning the rules by which these basic elements are combined from the level of sound to the level of sentence. It has been regarded as a process of mastering a succession of steps, each one building on the one before. Teachers present the target language in ready-to-assimilate pieces, starting with the easy parts and gradually moving towards the harder parts. Learners must master each part sequentially and incorporate it into their knowledge of the target language.
By contrast, the present view of language learning , mainly based upon research findings in linguistics, psychology, and pedagogy, is that learners do not acquire the target language in the order it is presented to them, regardless of how careful and thoughtful the teaches and textbook writers are in organizing the process. As Ellis puts it, language learning is a developmental, organic process that follows its own internal agenda. Errors are not necessarily the result of bad learning, but are part of the natural process of inter-language forms gradually moving towards target forms (Tian Jinping, 2006).
Such a view of language learning has deepened implications for language teaching, and has resulted in the development of TBLT. Foster states that TBLT gives learners tasks to transact, rather than items to learn, provides an environment which best promotes the natural language learning process. By engaging in meaningful activities, such as problem-solving, role-playing, discussions, etc., the learner’s inter-language system is stretched and expanded. These tasks rely on a successful transfer of meaning in order to be completed, and are supposed to focus the learners’ attention more closely on the comprehensibility of the language they and their partners are using, thus increasing the likelihood that inter-language forms will be pushed towards target language norms (Tian Jinping, 2006).
3.0 Teacher’s Roles in TBET
3.1 Teacher’s Roles in Traditional English Teaching and Their Limits
In traditional teaching, the goal of learning English for students is grasping language knowledge, acquiring ability to read and translate and getting a high mark in the examination. Thus, teacher is mainly the language explainer, controller and evaluator of students’ behavior. Teacher has previously got ready for all the answers of the questions. He gives detail explanation of every language points especially grammar knowledge and evaluates students’ answer according to the standard one. Students’ major task is to absorb all these knowledge and “standards”.
We should admit traditional teaching has contributed a lot to the social development in the past years and most English teachers are responsible for their students. However, the limits of it are obvious.
First, students lose desire to learn English gradually. Most students desire to perform well in English classes from the first lesson, but gradually they lose interests as a result of their learning experience. William Glasser states that very few children come to school labelled as failures. It is school and teachers that pin the label of failure on children. In traditional areas, teachers emphasize much more on the English tests and grades, students are usually compelled to do a lot of practices and homework mechanically and usually these tasks are irrelevant to their interests or life (Qi Xueyin, 2005).
Second, students lose independent learning ability.In traditional teacher-centered class, teacher is the controller, students followed him mechanically without their own personal styles. Many researches have demonstrated that feeling of being in control of events is associated with greater achievement. If students believe that learning is controlled by themselves, they may work hard to achieve success. No two learners will learn the same thing precisely in the same way, therefore, the single strategy given by the teacher is equal to killing the creativeness and independent learning ability of students. As a result, students greatly and gradually depend on teachers instead of themselves.
Third, teacher himself loses interest in teaching. Traditional teaching focus on the teaching of vocabulary, grammar points and sentence structure, teacher’s books are full of language points which they are to present, drill and exploit. But they easily and gradually lose enthusiasm because of the mechanism of the teac hing. It’s time for teachers to refresh their view and changing their roles in EFL teaching.
Fourth, it couldn’t meet the requirements of the new English Curriculum Standard. With the development of modern educational theory and the reform of traditional teaching model, the teaching instructional ideas and strategies have changed a lot in English language teaching. The English Curriculum Standard for the High School of the Fulltime Compulsory Education, made by the Ministry of Education of People’s Republic of China in 2001, requires that English teacher’s teaching principle, teaching strategy and teaching method should meet the demand of new curriculum. Classroom teaching should reform the old-fashioned and teacher-centered model, in which only book knowled ge is taught in classroom….we should add some tasks to the classroom activities so that the students can have the chance of expressing their ideas. Students should be encouraged to develop the ability to coordinate with others (He Lili, 2006).
From these points, we can see that the traditional teacher-centered teaching could not meet the demand of English teaching. TBLT has acted as an important role in English teaching today.
3.2 Teacher’s Roles in TBET
In TBE T classes, teacher’s goal is to create atmosphere of learning English, design good tasks and encourage students to communicate in English. Thus, teacher’s role s are determined to be facilitative. To sum up, teacher should act as introducer, activator, organizer, prompter,
supporter, evaluator, language instructor, reflector and researcher accordingly at different task stages.
3.2.1 Teacher Acts as an Introducer, Activator and Organizer at the Stage of Pre-task
At first, teacher is an introducer. He should choose a topic based on the text materials and students’ interests. It is in doing this that teachers have the most freedom and most challenge, and the teacher can also exert creativeness in an unlimited way. Before the class, teacher should have a through understanding of the text materials and students’ characteristics.
After introducing the topic, teacher has to arise students’ desire to speak and communicate in English. As an activator, he should be good at creating learning atmosphere. Offering topic related words and phrases will help activate s tudents’ mind.
Organization is necessary before task-cycle, instructions should be given concisely and clearly so that students know what the task is and how to complete it. Sometimes, a demonstration done by the teacher is necessary.
3.2.2 Teacher Acts as a Prompter and Supporter at the Stage of Task-cycle
During the task, students are busy doing the activity. It doesn’t mean teacher is totally an audience. He should walk around the classroom and watch students’ doing. If some students are not doing the relevant activity, he should warn them. If some students do not know how to start the activity, he should give them some hints, if students complete with a very usual result, he can elicit more by saying “anything else?” “If you…what it will be?”.
As a supporter, teacher mainly has two things to do. First, help students set up confidence in communicating in English. It’s difficult for some students to overcome the shyness and the anxious state of mind in speaking English, especially for those who are not good at English. Teacher should always encourage them, such sentences as “Come on, you are great!”“You can do it, I believe you!” can be used. Second, offer help to students when necessary. While facing difficulties, students are encouraged to solve them by themselves. However, sometimes, they need teacher’s help to complete the task, such as the lacking of knowledge, teacher should offer students timely consulting service so that students can make an active study during the task.
3.2.3 Teacher Acts as an Evaluator and Language Instructor at the Stage of Language-focus
After t he activities, it’s time for teachers to evaluate students’ agreements, stu dy strategies, ability, skills, attitude, and emotion and so on. While doing so, teachers had better use relaxed and open descriptive evaluation. They may evaluate by observing, talking, using questions or letting students evaluate themselves. There are many types of evaluation, such as the evaluation of students’ feedback, th e evaluation of students’ behavior in doing activities, the evaluation of mid-term examinations, etc. Teachers can adopt different methods of evaluation according to different types.
During the task-cycle, students inevitably have troubles in some language points. At the stage of language-focus, as an language instructor, teacher should give necessary explanation of the language points. Enough meaningful exercises will help students acquire the new points. The aim of doing so is to develop students’ ability of acquiring, analyzing, judging and using English.
3.2.4 Teacher Acts as a Reflector and Researcher after Teaching
Reflection is helpful for teachers to improve their teaching ability. Students’ tasks have ended, but it doesn’t mean teacher’s job has fi nished. What has happened in lessons, what should teacher do next time, the good points in encouraging students, other alternative means of achieving goals are all questions teachers can reflect. The remembrance of the past is the teacher of the future. As a good teacher, he is far from enough just repeating his former teaching experience. Only those who are good at learning from former experience and absorbing from lessons can improve their teaching ability and become experts.
Researching will help an inexperienced teacher become a professional one. There are many areas deserving teacher’s researching, such as advanced teaching theory, textbooks, students’ characteristics, the local teaching condition, and their personal styles and so on. After researching, a teacher can get clear what and how he should teach. A famous American headmaster once said that a teacher who can only teach is not a good teacher, but those who can both teach and research can be good teachers, researchers, or educationalists (Huang Shuyun,
2004).
All in all, in TBET classes, teacher should follow students-centered principle. He should not overcontrol the class. Teacher acts different roles at different stages so that activities can run smoothly and efficiently. At the same time, teacher themselves should be good at reflection and researching.
3.3 Reasons and Significance of Changing T eacher’s Roles
There are many researches and theories about teacher’s role s in English language teaching. Although their views are different, one point is sure, that is, it’s necessary to change teacher’s roles. Why should teachers change their roles in English teaching? Generally speaking, there are five reasons:
First, the changing of teacher’s role s mainly originated in the development of teaching approach. Compared with the traditional approach, TBET is more scientific and effective. It changes the focus, from teaching perspective to learning perspective, and the meaningful learning process instead of the product is put in the primary place. Besides, the learning units are more attractive and interesting, students are motivated to learn in TBET.
Second, reformation of education centered on curriculums has been carried out in the countries all over the world, and the changing of teacher’s role s is one of the content. In china, the new English Curriculum Standard has been carried out, which states tha t English teacher’s teaching principle, teaching strategy and teaching method should meet the demand of new curriculum. Therefore, the changing of English teacher’s role s has become a trend.
Third, TBET meets the requirements of learners. Traditionally, learners are busy in remembering words or phrases, finishing exercises and dealing with all kinds of examinations. However, when communicating with foreigners, they couldn’t understand them, let alone communicate with them in English. More and more learners like improving English by communication. TBET offers them opportunities and arises their interests of learning English. They dare to speak and don’t worry about their mistakes. In TBET, they can achieve the aim of learning English, that is, learning is for using.
Fourth, TBET can benefit teacher’s development. One important standard of good teachers in traditional teaching is students’ high grades. Therefore, teachers used to explain knowledge
mechanically, give standards, correct mistakes and have exams. On one hand, students lose interests in study. On the other hand, teachers themselves lose enthusiasm in teaching, let alone develop their professional qualities.
Fifth, the development of multi-media technology based on the internet presents new requirements to teachers. Teachers should develop their qualities and competence to meet the new situation.
4.0 Suggestions for Chinese English Teachers
4.1 Changing View
Implementing TBET, English teachers should change their view first. Teachers should make it clear that the traditional teacher-centered English teaching isn’t scientific and effective enough, and it affects the English teaching effect and students’ ability of adapting to the future society. Thus it has become a must to change teacher’s role s. Only by acquiring the basic theory of scientific teaching, trying to create learning situation and opportunities for students and emphasizing the students’ comprehensive ability of using language, Chinese English teaching can adapt to the development of society.
4.2 Analyzing and Developing Curriculum Resources
Task plays an important role in TBET. Good design originates from good combination of curriculum resources and students’interests and need. Therefore, analyzing and developing curriculum resources are very important.
Analyzing new curriculum can help teacher have a better understanding of the nature of this curriculum reform, the structure of textbooks and develop a common vocabulary and framework for further collaboration and learning. Developing curriculum resources means creatively utilizing curriculum resources and put students’ interests and need into consideration. Based on the analysis of the curriculum resources, it can be seen that a unit of new English curriculum should be finished in six periods. If every item is taught carefully, the pace of teaching has to be slowed down and it’s not necessary. Certain contents can be omitted to save time; certain contents should be supplemented according to students’attitudes, feelings and teaching strategies. If necessary, the order of the component parts can be changed.
4.3 Teaching According to Reality
TBLT is an effective and scientific teaching, but how to use it especially in the real English classroom is not so easy. As we know, china is a country with a vast territory, teachers from different places face different students, different teaching environments, therefore, it is impossible to solve all teaching problems only according to one teaching theory.
Teacher is the key factor in TBET. They should have classes combining both the theory and the reality. The ethic of TBET is creating real situation and promoting students to use English as a communicative language. Therefore, lesson plan, class activity and the form of homework can be various as long as the ethic is unchanged. It should be remembered that an approach is effective only when it is appropriate to the teaching context. Teacher’s teaching methods should combine the teaching context and the merits of TBET to serve the purpose of teaching objectives and the needs of students.
4.4 Self-development
Self-development is necessary. It means becoming a learner, learning from your own experiences as well as those of others to improve your teaching skills. Refresh your knowledge such as new teaching theory, foreign culture, topics that students are interested in and so on to enlarge your view. Suggestions are followed.
1) Constant reflection
Reflecting what you have done in each lesson frequently is one important and profitable way to develop your teaching ability. You may ask yourself the following questions.
a. How effective was the lesson in general?
b. What good points were there? Why were they good, and how could I develop them further?
c. What weak points were there? Why were they weak and how could I handle them better?
You can take a note at the bottom of your plan immediately after the lesson, then reflect positive and negative points in your teaching. Maybe it’s difficult to do so at first as your experience is limited, but gradually you will easily find the underlying reasons for your success and failures in your teaching.
2) Sharing with colleagues
Each teacher has his or her unique advantages in language teaching. It is a matter of professional ethics that stuff of any educational institution should work together, not to against one anther or in isolation. Sharing experiences and ideas, and it can give you a better perspective on your own work.
3) To be a learner
If teachers want to give students a bowl of water, they themselves must have a bucket of water (Huang Shuyun, 2004). This metaphor suggests new situations, new theories and new curriculum standard requiring much more of teacher’s ability and knowledge. Thus, teachers should study constantly, and even learn from students actively.
5.0 Conclusion
TBET follows students-centered principle rather than teacher-centered principle. It provides a circumstance for students to build up their confidence, cultivates a good learning habit, develops their self-study ability and forms effective study strategies. Thus, the aim of English teaching can be achieved.
In implementing this approach, teacher is the key factor, therefore, English teachers should change their views and make clear what their roles should be in this approach. Generally speaking, teachers should act as introducer, activator, organizer, prompter, supporter, evaluator and reflector accordingly at different task stages.
Besides, English teachers should develop their teaching methods based on both the advanced teaching theory and the teaching context. Self-development is also necessary so as to follow the new trend of English teaching.
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佳能镜头介绍范文 导语：当你有了一款性能相对来说还算是不错的相机的时候， 可依然还是拍不出自己理想的照片，也许是你的镜头不合适，那么，我在这里为你推荐几款佳能镜头以及一些简单佳能镜头维修知识。 佳能镜头一 佳能镜头EF-S18-200mmf/3.5-5.6IS广角镜头的尽头结构为12组16片，最近对焦距离为0.45m，放大倍率为0.24m，最近对焦距为0.45m。涵盖广角到长焦的11倍超大变焦比镜头，带IS防抖功功能，效果相当于提高约4档快门速度，采用两片UD超低色散镜片和两片 非球面镜片，带来出色画质，优化的镜头镀膜及镜片位置，能够有效抑制鬼影和眩光。 采用圆形光圈，具有出色背景虚化效果，高速CPU和优化的对 焦算法，为我们带来高速自动对焦，而且还配备镜头变焦环佳能镜头报价在4050元。 佳能镜头二 佳能镜头EF-S17-85mmf/4-5.6ISUSM广角镜头的性价比要比 EF-S18-55mmf/3.5-5.6IS高出很多，镜头结构为12组17片，最大 光圈为F4.0，镜头的最近对焦距离是0.35米，图像放大率是0.2倍。 佳能EF-S17-85mmf/4-5.6ISUSM广角镜头相当于27-136mm视角。内置影像稳定器，相当于提高3档快门速度。使用玻璃铸模双面非球面镜片和优化的镜头镀膜，成像素质优异。采用圆形光圈，可全时手动对焦。这款佳能镜头在中关村产品报价中的价格为3700。
佳能镜头三 佳能镜头EF70-200mmF2.8LISIIUSM镜头的光学结构是19组23枚镜片，全画幅、长焦镜头类型，镜头可用于标准镜头，中长焦镜头,远摄镜头;最大光圈F2.8，最小光圈F32，最近对焦距离在120cm;光圈叶片数8片，支持4重防抖。 还配备了IS光学影像稳定器，效果相当于提高最多4档快门速度。同时能自动判断拍摄场景所需的防抖模式，可以在普通防抖和追随防抖两种模式中切换。这个型号的佳能镜头的价位大概在11600元左右。 佳能镜头维修 1、佳能镜头简单维修需要准备专用维修镜头螺丝刀、开镜器、吹气泵、镜头清洁剂、抹镜纸; 2、先拆开镜头检查所有零件、镜片、控制器电路板与电线是否有损坏; 3、按照型号镜头图纸的零件编号来订购更换损害的零部件。
佳能镜头扫盲 买单反相机不是买机身，而是买镜头，至少是买机身和镜头的组合。 这里先介绍几套APS幅面的DSLR常见的镜头配置 P：优点 C：缺点 一、单镜头的选择 1.成本最低，性价比最高 EF-S 18-55/3.5-5.6 只有二手的看成色￥400上下 P：广角长焦都沾上，关键是便宜好用 C：就花了这么点钱来说，没什么可说的 我常说看得起套头的人，会使用套头的人，常常让拿着数nW器材的人大吃一惊。 也可以选择低EF-S 18-55/3.5-5.6II、EF-S 18-55/3.5-5.6 USM版。 2. 成本最低，性价比最高II EF50/1.8II ￥750 P：成像相当不错 C：焦段严重不足，做工很差，只适合入门 不少人对50/1.8II的做工严重不屑，但使用50/1.8II 的人很多对其性能价格很满意。不要以貌取镜，也不要想凭它争面子，要么它拍出的片子说话。
3.一镜足矣 EF-S 17-85/4-5.6 IS USM ￥4800 P：焦段太合适了，IS用了都说好， C：性价比略低 FSLR上，EF28-135/3.5-5.6 IS USM是非常经典的头头，价格不错、成像不错，I、U俱全。17-85作为对应的EF-S 版本，虽然价格高了不少，光圈略小，但无法阻止它成为单镜头配置的好选择。 4.失去长焦，得到红圈 EF17-40/4L USM ￥6000 P：非常好的广角头，不论价格、成像还是做工。 C：缺乏长焦，遮光罩太难看。 有评测指出，17-40L在广角段成像优于昂贵的16-35L。它外形很象16-35L足够你亮骚、机械性能很好、使用和成像都让人满意。 5. 拥有F2.8=拥抱高端 EF-S 17-55mm f/2.8 IS USM ￥8000 P：不画红圈的L头，IS、USM、恒定F2.8一样都不少 C：你真的不考虑全副了吗？ Canon为了APS尺寸打造的主力镜头，性能成像没啥说的。不标L有两种可能：Canon认为L头应该是全副的；这个头毕竟是塑料的，与24-70之流还是有差距的。唯一的问
佳能数码相机镜头标识详解 AFD：Arc-Form Drive 弧形马达 为早期EF镜头的AF驱动而开发的弧形直流马达。与USM马达不同，AFD 马达对焦是有声的。 DO：Multi- Layer Diffractive Optical Element 多层衍射光学元件 Canon于2000年9月4日宣布研制成功世界上第一片用于照相机摄影镜头中的“多层衍射光学元件”。多层衍射光学镜片同时具有萤石和非球面镜片的特性，所以该镜片的推出，是光学工业的一个里程碑。衍射光学元件最重要的特性是波长合成结像的位置与折射光学元件的位置是反向的。在同一个光学系统中，将一片MLDOE与一片折射光学元件组合在一起，就能比萤石元件更有效地校正色散（色彩扩散）。而且，通过调整衍射光栅的节距（间隙），衍射光学元件可以具有与研磨及抛光的非球面镜片同样的光学特性，有效地校正球面以及其他像差。 代表镜头：EF 400/4 DO IS USM EF: Electronic Focus 电子对焦 佳能EOS相机的卡口名称，也是EOS原厂镜头的系列名称。 EMD：Electronic-Magnetic Diaphragm电磁光圈 EF镜头的电磁驱动光圈控制元件，是变形步进马达和光圈叶片的一体化组件，用数字信号控制，灵敏度和精确度都很高。 FL：Fluorite 莹石 一种氟化钙晶体，具有极低的色散，其控制色差的能力比UD镜片还要好。从严格的意义上来说，莹石不是玻璃，而是一种晶体。它的折射率很低（1.4）而且不受潮湿影响。莹石镜片一般不会暴露在外，所以你不大会直接接触到。莹石镜片不如普通玻璃耐冲击，但也不像想象中的那么易碎，所以在使用中并不需要特殊的照顾。
佳能单反600D详细说明 外观性能第1段 Canon600D的机身采用塑料材质，在保持小巧便携优点的同时，增加了表面蒙皮的面积，防滑性能有所提升，并且有效的提升了视觉感受，显得更有档次。本次与机身一同送测的是Canon新款18-55mm IS II 镜头，该镜头在外观方面也有一定的改变。下面，我们先来看看Canon600D的整体外观设计。 图为：Canon600D正面 Canon600D采用一块1800万像素CMOS传感器，传感器尺寸为22.3×14.9mm，是目前入门高端单反中像素最高的机型之一，最大支持拍摄5184×3456像素的照片。与1800万像素传感器搭配的是Canon 引以为豪的DIGIC 4高性能处理器，从Canon550D及60D可以看出，这个经典组合能够获得非常不错的画质。不过，Canon600D的核心硬件没有明显升级依然令许多人感到遗憾。 图为：Canon600D两侧，蒙皮面积大增 图为：Canon600D顶部
图为：Canon600D底面 整体来说，Canon600D的外观与550D没有太大的差别，亮点就是那块从60D上下放的可旋转液晶屏。不过，Canon600D的光学取景器与上代机型相比却有所缩水，放大倍率从0.87倍降至0.85倍，笔者仔细对比了两款机型的取景器大小，这0.02倍的差距虽然很微小，但心里难免有些不爽快。整体外观先说到这里，下面我们再来看看Canon600D的细节设计有什么不同。 Canon600D搭载了全新的18-55mm IS II套机镜头，与上代套头相比，该镜头在外观上有所变化，全黑的镜筒显得更加专业，4级防抖也能保证用户在暗光环境下手持不抖。从稍后的镜头分辨率测试成绩来看，新套头的光学结构虽无太大变化，不过中央分辨率依然非常惊人。 Canon600D搭载了新18-55mm IS II套机镜头 右肩区域增加了一个DISP.按钮，用于开关液晶屏
佳能粉丝必看八款最令你垂涎镜头推荐对于拥有佳能数码单反的朋友，相信对于好镜头的渴望肯定非常强烈。特别是那些能带来高画质表现的大光圈镜头和变焦镜头，如佳能24-70mm/F2.8L，定焦头85mm/F1.2L， 16-35mm/F2.8L II等。 镜头群 虽然不可否认，学习摄影的目的是为了拍摄出好的照片来，有时候我们都应该脱离简单的器材关注，而应该把精力放在拍摄技术、构图、后期修片等技术层面上去。只有这样，我们才能不至成为简单的器材党。 但是对于那些好的器材装备，相信任何一个摄影爱好者在看到后，都会为之激动和兴奋的，特别是在对比一款高端镜头和低端镜头的画质表现时，它们的差别往往是明显的，并且令人印象深刻的。那么如果你是一个佳能单反粉丝的话，你是否也对佳能那些高端镜头垂涎不已呢？让我们一起去看看以下几款镜头是否也是你一直以来梦寐以求的。 F2.8恒定光圈 最佳变焦头24-70mm惹人爱 编辑点评：一般都认识定焦头由于不能变焦，可以带来大光圈表现，导致大家会去选择定焦头。但不可否认的是变焦头的用途要比定焦头更广泛，在日常拍摄中也更常用到。而至于那些变焦头带恒定光圈的镜头，自然是大家最为倾心的，就比如佳能24-70mm/F2.8L。 佳能24-70镜头是属于L级别的专业中焦段变焦镜头。F2.8恒定大光圈，适用于全画幅和非全画幅机身。 该镜头采用2片非球面镜片，以及超低色散镜片和优化的镜头镀膜，在全焦范围内均可达到极高的成像质量和更快的自动对焦速度，同时红圈镜头都有密封设计，具备良好的防尘防水溅功能，适合全天候使用。目前佳能24-70L F2.8镜头的价格为10199元，带发票。
买单反相机不是买机身，而是买镜头，至少是买机身和镜头的组合。 A:优点 S:缺点 C:简评 一、一镜当家 单个镜头是最基本的配置，也是多镜头搭配的基础。一般来说，这个头应该选使用频率最高的挂机头，通常是标准变焦镜头。 （一）入门阶段 1. 成本最低，性价比最高 EF-S 18-55mm f/3.5-5.6 IS 市场参考价￥700 A：便宜好用，可圈可点 S：就花了这么点钱来说，没什么可说的 C：撞针常说看得起套头的人，会用套头的人，常常让拿着数万块器材的人大吃一惊。其实大部分换掉这个头的人当时并不知道它到底哪儿不好，为什么要升级。 2. 长一寸强一寸 EF-S 18-135mm f/3.5-5.6 IS 市场参考价￥2300 A：常用焦段足足的 S：价格再便宜点就好了 C：和上下两枚镜头没有本质区别，焦段还不错，目前的价格，可以接受。 3.一镜走天下 EF-S 18-200mm f/3.5-5.6 IS
市场参考价￥3200 A：焦段充足，走遍天下都不换 S：成像一般般 C：对于家庭摄影和初学者来说省去很多麻烦，男女通用老少咸宜。这款镜头价格可能会有所调整，将会是副产镜头的杀手。 4.过气主力 EF 28-135mm f/3.5-5.6 IS USM 市场参考价￥3280 A：胶卷时代大众镜头的中坚力量 S：陈旧，焦段难受，该下岗了 C：作为一个前数码时代的镜头，虽然性能面面俱到，但今天看哪一方面都不咋地。眼下Canon还留着这个型号大约一方面是借着以前的名声赚取剩余价值，另一方面是照顾还揣着老胶卷机身舍不得买红圈的消费者。 （二）初烧阶段 1.一镜足矣 EF-S 15-85mm f/3.5-5.6 IS USM
佳能红圈L级镜头全面导购 2009-12-02 00:09:07| 分类：摄影器材| 标签：|字号大中小订阅 佳能红圈镜头一直都是使用佳能单反的专业摄影师的标准配置也是C家摄影器材爱好者关心的热点。红圈镜头凭借自己严实的做工和出色的成像吸引了众多摄影爱好者的目光，不过L级镜头的价格不菲，动辄上万是非常正常的事情，最便宜的也要5千多 元。 L级镜头是佳能的专业级镜头，在镜头型号中的光圈参数后都加有大写“L”的字样，镜头前端都有橙红色饰圈表明这支镜头极尽奢侈, 华贵的身份。佳能L级镜头除去个别特殊型号外大多都具有迅速宁静的超声波对焦马达，防滴水防尘性能，非球面镜片和超低色散镜片，同时支持胶片相机和数码相机使用，L级镜头当中还有着众多恒定光圈变 焦产品以及大光圈定焦产品。 出色的设计带来绝佳的成像，扎实的做工带来稳定的性能，因此佳能L级镜头成为无数专业摄影师的首选，作为佳能的粉丝，红圈L级镜头的魅力是无可抵挡的。今天我们就来关注一下目前市场上有售的佳能红圈镜头。 专业变焦必备篇 L级镜头是佳能顶级器材的代表，而L级镜头之间按照性能高低也分为不同档次。最高端镜头的用户通常是记者和其它职业摄影师，我们平时在新闻里也时常可以看见这 些顶级器材的身影。
出镜率最高的一只佳能超广角变焦镜头，打开电视几乎在每天各种新闻当中都能看见许多16-35mm的身影。这支EF 16-35mm F2.8L II USM 镜头是EF 16-35mm f/2.8L USM镜头的全面升级版。使用了2片UD超低色散镜片以及3片非球面镜，优化的镜片镀膜和镜片位置有效抑制鬼影和眩光。圆形光圈带来出色的焦外成像，环形超声波马达、高速CPU和优化的自动对焦算法使对焦安静快速准确，实现全时手动对焦功能。镜身具有出色的防水滴防尘性能，光学系统全部采用无铅玻璃，装备了新开发的82mm 口径保护滤镜。 佳能EF 16-35mm f/2.8L II USM 焦距：16-35mm 视角：108° 10' - 63° 最大光圈：全程恒定F2.8 光圈叶片：9片圆形光圈 镜头内部结构：12组16枚 最近对焦距离：0.28 m 最大放大率：0.22 倍 滤镜口径：82 mm 镜头尺寸：88.5 x 111.6 mm 重量：635克
P：优点C：缺点 一、单镜头的选择 1.成本最低，性价比最高 EF-S 18-55/3.5-5.6 只有二手的看成色￥400上下 P：广角长焦都沾上，关键是便宜好用 C：就花了这么点钱来说，没什么可说的 我常说看得起套头的人，会使用套头的人，常常让拿着数nW器材的人大吃一惊。也可以选择低EF-S 18-55/3.5-5.6II、EF-S 18-55/3.5-5.6 USM版。 2. 成本最低，性价比最高II EF50/1.8II ￥750 P：成像相当不错 C：焦段严重不足，做工很差，只适合入门
不少人对50/1.8II的做工严重不屑，但使用50/1.8II的人很多对其性能价格很满意。不要以貌取镜，也不要想凭它争面子，要么它拍出的片子说话。 3.一镜足矣 EF-S 17-85/4-5.6 IS USM ￥4800 P：焦段太合适了，IS用了都说好， C：性价比略低 FSLR上，EF28-135/3.5-5.6 IS USM是非常经典的头头，价格不错、成像不错，I、U俱全。17-85作为对应的EF-S版本，虽然价格高了不少，光圈略小，但无法阻止它成为单镜头配置的好选择。 4.失去长焦，得到红圈 EF17-40/4L USM ￥6000 P：非常好的广角头，不论价格、成像还是做工。 C：缺乏长焦，遮光罩太难看。
有评测指出，17-40L在广角段成像优于昂贵的16-35L。它外形很象16-35L足够你亮骚、机械性能很好、使用和成像都让人满意。 5. 拥有F2.8=拥抱高端 EF-S 17-55mm f/2.8 IS USM ￥8000 P：不画红圈的L头，IS、USM、恒定F2.8一样都不少 C：你真的不考虑全副了吗？ Canon为了APS尺寸打造的主力镜头，性能成像没啥说的。不标L有两种可能：Canon认为L头应该是全副的；这个头毕竟是塑料的，与24-70之流还是有差距的。唯一的问题是为APS镜头投入这么多，将来换全副相机的时候怎么办？ 二、双镜头选择 轻便方便、不失体面 （一）变焦+定焦 变焦+定焦有一个好处，你可以获得足够的焦段和一个很大的光圈，价格也便宜。 首先解释一点，我在这里推荐广角定焦+标变的组合。如果你目前还需要听取别人的建议选择镜头，那么我必须告诉你，广角是较难控制的焦段，初学者不容易掌握，不买专门的广角镜头，有个兼顾广角的标变就好，可以从前面介绍的那些里面选择。 这类组合最便宜的莫过于EF-S 18-55/3.5-5.6（II、USM）+ EF50/1.8II，前面也点评过这两个镜头。 如果你希望享受点定焦品质的话可以选择这些： 1. EF50/1.4USM
佳能单反相机功能件介绍 相机能够根据拍摄场景自动进行各种设置 EOS 600D搭载了场景智能自动，可实现自动白平衡、自动亮度优化、自动照片风格、自动曝光和自动对焦这5种自动功能的智能连动。此模式下，相机会依据EOS场景分析系统获得的信息，自行判断并进行符合人物、运动被摄体、自然风光、室外场景、黄昏或高色彩饱和度被摄体等的相应设置。此外，由于搭载了场景智能自动，模式转盘上的标识也进行了重新设计，从原来的全自动模式标示变为由代表自动的“A”和具有进化、统合含义的“+”组合而成的新标识。 相机能够自动识别多种拍摄场景 动作以及分析相机与被摄体的距离等信息，并以这些信息为基础自动判别相应的拍摄场景。相机能够识别的场景包括人物、自然风光、室外、黄昏、高色彩饱和度以及逆光等。然后，相机会根据分析所得信息来恰当地自动调节各种设置等。例如，在拍摄人物时相机会进行自动调节，从而获得较以往更加自然的肌肤颜色。EOS 600D中的自动照片风格也能得到准确控制。此外，自动白平衡和自动亮度优化的性能也得到了提升，使相机可自动控制的场景数量进一步增加。这样，便使拍摄者在拍摄时能更加专注于构图和快门时机的把握。 可根据拍摄场景自动生成照片风格 EOS 600D在佳能自行研发的图像处理功能——照片风格中添加了新开发的“自动”模式。此模式下，相机能够以EOS场景分析系统获得的数据为基础，根据不同场景进行调节，“创造”出恰当的照片风格。在拍摄晴空、含有大片绿色的大自然、室外场景以及黄昏时，蓝天、绿色和晚霞都会表现得十分鲜艳。 依据场景识别的结果调节色调 白平衡是一种能够对不同光源造成的偏色现象进行准确补偿的功能。EOS 600D搭载了能够准确识别拍摄场景的EOS场景分析系统，使自动白平衡的精度得到提升，尤其是可展现出比之前机型更加准确的颜色。
佳能镜头术语与标识详解 发布日期：2012-12-17 佳能在产的镜头一共有60余支。由于佳能在改用电子卡口（EF卡口）后放弃了对既往手动镜头的支持，这使得当前市场上能使用的佳能镜头不像尼康镜头一样繁杂。然而，这些镜头依然足够让人头痛，尤其是初学者简直无法分辨不同的镜头。区分这些镜头的唯一方法是看懂每一支镜头的标识并且理解这些术语。尤其是有些镜头焦段完全相同，只能依靠EF-S、IS、USM等镜头标识加以区别。看懂这些镜头术语和缩略语有几个好处： 首先，可以让自己更方便地了解佳能镜头阵营中的镜头，以方便选择自己需要的镜头。其次，能够识别无良商家的骗术。有时候商家会故意混淆两支镜头，用一支价格很低的镜头冒充价格很高的镜头。比如，佳能在70-200mm焦段以及70-300mm焦段都拥有大量不同的镜头，这些镜头价差巨大。这时候，准确了解镜头术语就能够避免上当受骗。最后，镜头和相机存在匹配的问题。有些镜头无法在某些相机上使用，比如EF-S镜头无法在全画幅相机上使用。只有了解这些镜头术语和标识的含义，才能够选择合适自己相机的镜头，以避免发生选择镜头的错误。 虽然这些镜头术语看起来很深奥，其实理解起来很简单。如果你只想了解最重要的信息，那么以下几点是你必须记住的： 1. EF-S镜头只能用于APS-C格式镜头，不能在全画幅格式相机上使用。EF-M镜头只能用于EF-M格式可换镜头单电相机。 2. IS代表镜头带有防抖系统，但是不同的IS防抖系统对快门速度的补偿不同，这些差异无法通过IS标签被识别。 3. USM代表镜头装备了超声波马达。但是，USM马达具有环形和微型的区分，这种区分也无法通过USM标签被识别。 如果你希望了解得更详细一些，下面这张表格为你解释了目前在产佳能镜头的大多数术语与标识。 在产佳能EF镜头术语与标识解释 镜头术语与标识实际意义 EF 佳能EF 35mm f/1.4L USM EF是佳能单反镜头的品牌，代表电子对焦镜头。所有的佳能镜头都被称为 EF镜头，这也是佳能镜头的官方称呼。
奢华的精品佳能红圈L级镜头全面导购
奢华的精品佳能红圈L级镜头全面导 购 [pconline] 2008-01-08 09:07:46 作者： Kim 责任编辑： jinlin L级镜头是佳能的专业级镜头，在镜头型号中的光圈参数后都加有大写“L”的字样，镜头前端都有橙红色饰圈表明这支镜头极尽奢侈, 华贵的身份。佳能L级镜头除去个别特殊型号外大多都具有迅速宁静的超声波对焦马达，防滴水防尘性能，非球面镜片和超低色散镜片，同时支持胶片相机和数码相机使用，L级镜头当中还有着众多恒定光圈变焦产品以及大光圈定焦产品。 出色的设计带来绝佳的成像，扎实的做工带来稳定的性能，因此佳能L级镜头成为无数专业摄影师的首选，作为佳能的粉丝，红圈L级镜头的魅力是无可抵挡的。今天我们就来关注一下目前市场上有售的佳能红圈镜头。 专业变焦必备篇 L级镜头是佳能顶级器材的代表，而L级镜头之间按照性能高低也分为不同档次。最高端镜头的用户通常是记者和其它职业摄影师，我们平时在新闻里也时常可以看见这些顶级器材的身影。
佳能EF 16-35/2.8LⅡ USM 价格：11600元 出镜率最高的一只佳能超广角变焦镜头，打开电视几乎在每天各种新闻当中都能看见许多16-35mm的身影。这支EF 16-35mm F2.8L II USM 镜头是EF 16-35mm f/2.8L USM镜头的全面升级版。使用了2片UD超低色散镜片以及3片非球面镜，优化的镜片镀膜和镜片位置有效抑制鬼影和眩光。圆形光圈带来出色的焦外成像，环形超声波马达、高速CPU和优化的自动对焦算法使对焦安静快速准确，实现全时手动对焦功能。镜身具有出色的防水滴防尘性能，光学系统全部采用无铅玻璃，装备了新开发的82mm口径保护滤镜。 佳能 EF 16-35mm f/2.8L II USM图库评测论坛报价 焦距：16-35mm 视角：108° 10' - 63° 最大光圈：全程恒定F2.8 光圈叶片：9片圆形光圈
完美影像享受佳能L红圈镜头的历史 相机之家日期: 2008-9-18 类型: 转载 在今天摄影界流传着这样一句话：“不要怀疑佳能的L镜头，一如不要信赖那些非L镜头” 。这句话对于普通镜头的贬低当然过于偏颇，但在摄影人看来，它对于佳能L镜头无以复加推崇却毫不过分。 这些前端标记着红色圆圈的佳能135镜头将力与美、刚与柔汇集于一身，即便忽略所有的功用价值，也可以作为尤物放在男人的手掌上把玩。它们在影像界的地位和影响如同汽车业的宝马：两者都已经脱离了一般“工具”的范畴，进而成为一种品味和格调象征。 究竟什么是L镜头？这个问题有着太多种解答：有人认为它们是佳能的专业镜头系列，专为摄影师所用；有人认为它们是蕴涵领先光学技术的镜头，具备高超的光学素质和成像质量；有人认为L表示更大镜头，可以容纳更大的光圈和更多的功能，或是更精密而坚固的外表；还有人戏虐L就是“捞钱”的意思……事实上佳能自己对这个红色“L”的解释是一个非常简单的单词：Luxury。不必是专业人士，也无需了解萤石、非球面、色散畸变之类的术语，L镜头所给与使用者的完全是完美的影像享受和奢华的拍摄体验。 L镜头的源起 L镜头对于完美影像的追求可以追溯到四个重要的历史节点。 吉田五郎内田三郎精机光学研究所建立之初所在地 首先当然是1933年，两个日本青年吉田五郎和内田三郎怀揣梦想在东京麻布六本木设立精机光学研究所，开始研发小型照相机，这就是佳能研发中心的前身。
Kwanon海报 Kwanon原型机 Kwanon标志 第二年，他们仿照徕卡相机，试制了日本第一台135焦平面快门照相机“Kwanon”（日语“观音”的音译，其标志就是一尊观音坐像，宣传语写到“伊号潜水艇、九二式战斗机和 Kwanon照相机都是世界第一”）。
佳能单反镜头知识 EF镜头的基础知识 EF镜头名解读 EF镜头名由各种数字和字母等组成。所有的数值和符号都有各自的含义，明白了这些含义就能大概了解镜头的特征。镜头名大致分为4部分：①镜头的类型、②焦距、③最大光圈、④镜头特性。另外其排列顺序也有规则，一般的镜头都是按①-④的顺序排列，如果表示镜头特性的符号较多，如EF 70-200mm f/2.8L IS II USM的镜头名，这些符号就依次排列在最后。 镜头种类 EF 适用于EOS相机卡口的几乎所有镜头均采用此标记。如果是EF，则不仅可用于胶片单反相机，还可用于全画幅、APS-H画幅以及APS-C画幅数码单反相机。 EF-S APS-C画幅EOS数码单反相机专用镜头。S为Small Image Circle（小成像圈）的字首缩写。 TS-E 可将光学结构中一部分镜片倾斜或偏移的特殊镜头的总称。备有焦距分别为17mm、24mm、45mm、90mm的4款镜头。 MP-E 最大放大倍率在1倍以上的“MP-E 65mm f/2.8 1-5微距摄影”镜头所使用的名称。MP是Macro Photo（微距摄影）的缩写。 焦距 表示镜头焦距的数值。定焦镜头采用单一数值表示，变焦镜头分别标记焦距范围两端的数值 最大光圈 表示镜头亮度的数值。定焦镜头采用单一数值表示。变焦镜头中亮度不随焦距变化而变化的采用单一数值表示，最小光圈值随焦距变化而变化的镜头，有2个数
值分别表示广角端与远摄端的最大光圈。 镜头特性 L L为Luxury（奢华）的缩写，表示此镜头属于高端镜头。此标记仅赋予通过了佳能内部特别标准的具有优良光学性能的高端镜头。 USM 表示自动对焦机构的驱动装置采用了超声波马达（USM=Ultrasonic Motor）。USM 将超声波振动转换为旋转动力从而驱动对焦。 IS IS是Image Stabilizer（影像稳定器）的缩写，表示镜头内部搭载了光学式手抖动补偿机构。 II、III 镜头基本采用相同的光学设计结构，仅在细节上有微小差异时添加该标记。II、III表示是同一光学结构镜头的第2、3代。 DO 表示采用DO镜片（多层衍射光学元件）的镜头。其特征是可利用衍射改变光线路径，只用一片镜片对多种像差进行有效的补偿，此外还能够起到减轻镜头重量的作用。 其他 镜头种类反映其功能上的特征。微距镜头一般是最大放大倍率为0.5至1倍（等倍）的镜头。微距镜头中有可以进行等倍至5倍拍摄的1-5微距摄影镜头。另外还有具有柔焦效果的柔焦镜头，以及拥有180°以上宽广视角的鱼眼镜头等。 EF镜头的基础知识
器材小知识——佳能镜头编号的意义 佳能镜头编号,佳能镜头价格,佳能镜头报价,佳能镜头大全 佳能镜头编号含义镜头年份镜头查询 分享一下佳能镜头编号的含义，对想买二手头的朋友应该有参考意义。 第一个U:表示产地。还可以是F或O生产工厂代号： O：大分工厂 K：大分杵筑工厂 U：宇都宫工厂 F：福岛工厂 T：台湾工厂 S：滋贺长浜工厂 M：宮崎(可能 U = Utsunomiya, Japan F = Fukushima, Japan O = Oita, Japan 第二个字母是生产年份 A = 1986,
1961，。。。。，U = 2006, 1981，V = 2007, 1982，W = 2008, 1983，。。。。 A 1960 / 1986 J 1969 / 1995 S 1978 / 2004 B 1961 / 1987 K 1970 / 1996 T 1979 / 2005 C 1962 / 1988 L 1971 / 1997 U 1980 / 2006 D 1963 / 1989 M 1972 / 1998 V 1981 / 2007 E 1964 / 1990 N 1973 / 1999 W 1982 / 2008 F 1965 / 1991 O 1974 / 2000 X 1983 / 2009 G 1966 / 1992 P 1975 / 2001 Y 1984 / 2010 H 1967 / 1993 Q 1976 / 2002 Z 1985 / 2011 I 1968 / 1994 R 1977 / 2003 后面2个阿拉伯数字代表生产月：如01代表1月，09代表9月，11当然代表11月了。后续的2个阿拉伯数字没多大意义，
佳能镜头标识解惑和常用别名汇总（更新图片） 第一部分介绍是来自我们太平洋数码相机频道的文章 首先是示意图： 佳能镜头一般分为两大系列（佳能全画幅镜头是EF系列，非全画幅镜头是EF-S系列），上图便是其中的代表，我们可以看看两种型号有什么差别，详细解释请留意型号下面的号码。 ①EF：镜头系列名称，佳能的镜头卡口是EF卡口，中文全称是“全电子镜头接环（卡口）”，镜头与机身之间没有机械传动结构，全部是以电子触点操作。（佳能全画幅镜头是EF系列，非全画幅镜头是EF-S系列） ②70-200mm（15-85mm）：这是镜头的焦距，有范围的（例如70-200mm）代表这是一只变焦镜头，没有范围、只有一个定值（例如50mm）代表这是一只定焦镜头。 ③f/2.8（f/3.5-5.6）：这是代表这只镜头在不同焦段的最大光圈值。如果变焦镜头的最大光圈值是一个定值（例如f/2.8）代表这是一只恒定光圈镜头，在镜头的广角端和长焦端都能保持一定的最大光圈；如果变焦镜头的最大光圈值是一个范围值（例如f/3.5-5.6），前面一个数值代表该镜头在广角端的最大光圈，后面一个数值代表该镜头在长焦端的最大光圈。如果是定焦镜头，最大光圈是一个定值（特殊镜头除外）。 ④L：是英文luxury的缩写。如果在佳能镜头名称中带有“L”，则表示此镜头采用了佳能先进的技术和昂贵的材料，具有极佳成像素质。L镜头的明显标志是镜筒上醒目的红圈。 ⑤IS：表示采用了IS（IMAGE STABILIZER）影像稳定器，即光学防抖功能。 ⑥II：代表相同规格镜头的第二代（优化改进版之类）。 ⑦USM：表示镜头的自动对焦是利用超声波马达为动力来源。 ⑧EF-S：佳能在EF系列镜头基础上，通过缩小镜头成像圈大小，适应APS-C（非全画幅）数码单反较小的感光元件。EF-S系列镜头有着较低的设计、制造成本，适合入门级数码单反使用（当然也有EF-S的高级镜头），但是EF-S镜头不能用在佳能全画幅单反上，会损坏镜头和机身。 除了在镜头型号上的标识，镜头特性或者功能都有不同的标识，部分也会出现在其他镜头的型号上，现在就让我们来看看。 1、USM（超声波马达）：通过将超声波振动转换成转动能源的这一崭新原理，实现了几乎没有操作声的静音镜头驱动马达。1987年，佳能首次将之应用于EF 300mm f/2.8L USM，震惊了全世界的摄影师。而且，还以低耗电量实现了高效、高扭矩、高灵敏度的高速对焦。现在，
佳能镜头编号的含义 U:表示产地。还可以是F或O生产工厂代号： O：大分工厂 K：大分杵筑工厂 U：宇都宫工厂 F：福岛工厂 T：台湾工厂 S：滋贺长浜工厂 M：宮崎(可能 U = Utsunomiya, Japan F = Fukushima, Japan O = Oita, Japan 第二个字母是生产年份 比如A = 1961等A 1960 / 1986 J 1969 / 1995 S 1978 / 2004 B 1961 / 1987 K 1970 / 1996 T 1979 / 2005 C 1962 / 1988 L 1971 / 1997 U 1980 / 2006 D 1963 / 1989 M 1972 / 1998 V 1981 / 2007 E 1964 / 1990 N 1973 / 1999 W 1982 / 2008 F 1965 / 1991 O 1974 / 2000 X 1983 / 2009 G 1966 / 1992 P 1975 / 2001 Y 1984 / 2010 H 1967 / 1993 Q 1976 / 2002 Z 1985 / 2011 I 1968 / 1994 R 1977 / 2003 后面2个阿拉伯数字代表生产月：如01代表1月， 09代表9月，11当然代表11月了。后续的2个阿拉伯数字没多大意义，CANON内部标识！ 在后面两个是佳能内部的批号， 同一批的镜头，该号是一样的 UN**** 1999年 UO**** 2000年 UP**** 2001年 UQ**** 2002年 UR**** 2003年 US**** 2004年 UT**** 2005年 UU**** 2006年 UV**** 2007年 UW****2008年 UX****2009年 UY****2010年
八大品牌镜头技术标识讲解 镜头型号标识，正如一个镜头的身份识别系统一样，相同焦段相同光圈的镜头只有通过镜头标识来区分。正如AF-S VR 70-200mm F2.8G IF ED是尼康“小竹炮”而EF70-200mm F 2.8L IS USM是佳能“爱死小白”一样，AF-S、VR、G属于尼康镜头的标识而EF、L、IS、USM属于佳能镜头特有的标识，所以单单看镜头标识就可以分出是哪个厂家的哪款镜头。 佳能、尼康、宾得等厂商的AF镜头不下数百只，加上手动镜头更是数不胜数，如何来区分这些镜头？首先从了解它的镜头标识的含义开始。 有些标识是所有镜头厂家通用的，譬如AF表示自动对焦、F表示光圈、Fisheye表示鱼眼镜头、mm表示焦距、Zoom表示变焦镜头等等，但也有一些标识是一个或几个厂家特有的，所以需要对各个厂家的镜头标识作一个细致的介绍： 佳能镜头讲解： AFD：Arc-Form Drive 弧形马达，早期的EF镜头都搭载AFD马达，对焦速度不如USM 马达，对焦声音也比后者大。 AL：Aspherical非球面镜片。 DO：Multi- Layer Diffractive Optical Element 多层衍射光学镜片，佳能于2000年首次将它应用到镜头上，它同时具有萤石和非球面镜片的特性，能有效抑制色散和校正球面以及其他像差，目前主要用在长焦镜头领域，共有3只镜头：EF 400mm F4 DO IS USM、EF7 0-300mm F4.5-5.6 DO IS USM、EF800mm F5.6 DO IS USM。 EF:Electronic Focus 电子对焦，佳能EOS相机的卡口名称，也是佳能原厂镜头的系列名称。
佳能机身型号意义大全 例： CANON EOS 1DS MARK III A BCD E F A： EOS是指“Electro Optical System"的英文缩写，这个名字是佳能1985年开始研究新型自动对焦相机是确定的，它有两重含义：一方面,EOS是电子光学系统的，表明这个系统是以先进的电子光学技术为基础而发展的。另一方面EOS这个单词还有黎明女神的意思，佳能与1987年正式推出EOS系统，包括一系列可无限扩展的可更换镜头35毫米胶片及数码相机机身、镜头及附件。与此同时，系统兼容性亦不断提升，除单镜头反光相机及镜头外，也支持XL系列数码摄像机，使EOS成为极其全面的摄影系统。 B： 数字为1时，为佳能专业单反相机，如1D，1Ds。 数字为除1之外其他个位奇数时为佳能准专业单反相机,数字越小专业度越大，如5D，7D。 数字为十位数时，为佳能APS-C中档单反相机，通常为10的倍数值，数字大为最新产品，如30D，50D。 数字为百位时，为佳能APS-C入门级单反相机，通常为50的倍数，数字大为最新产品，如300D，450D。 数字千位数时为佳能APS-C普及型入门单反相机，目前只出过一款，1000D。 C： 字母D为数码单反的意思 D: 只有1D系列有这个后缀，有s的为全画幅（感光体为24X36mm）单反相机，没有后缀s的为APS-H（感光体为28.7X19.1mm）单反相机，等效镜头焦距要X1.3 E: 只有专业机和准专业机上有，MARK表示在基础机型上改进后的型号 F: 也只有专业机和准专业机上有，为不断改进的后顺序号，数字大为最新出品。 佳能机身俗称 大马三---CANON EOS 1DS MARK III 大兔子---CANON EOS 1DS MARK II 小兔子---CANON EOS 1D MARK II 小兔妞（也叫马克吐温）---CANON EOS 1D MARK II N 五弟---CANON EOS 5D 无敌兔－CANON EOS 5D II 塑料拖鞋－CANON EOS 400D 佳能镜头型号意义
● EF-S 18~55mm F3.5~5.6 II USM介绍 佳能入门单反上配备的EF-S 18~55mm F3.5~5.6 II USM套头被很多朋友认为是一直标准的“狗头”，光学性能非常一般。但我们觉得，这颗镜头作为初学者的练手装备还是非常合适的，并且低廉的价格，用起来也不必像使用L头那样小心翼翼。实惠扛造，或许是形容这颗狗头的最好词汇。 这颗EF-S标准变焦套头价格比较便宜，实惠扛造 今天，小编在网上发现一位网友手中的EF-S 18~55mm F3.5~5.6 II USM镜头出现了故障，因为他手中还有别的高档镜头，这支玩意也并不常用，即便修好了也难免有些鸡肋。所以人家干脆一不做二不休，直接给拆了。咱们可以也跟着上一堂镜头内部构造的知识普及课。
EF-S 18~55mm F3.5~5.6 II USM 首先我们来看看这颗镜头的大致性能，它的镜片结构为9组11枚，其中包含了1组非球面镜片。它采用圆形光圈设计，叶片数量为6片。最近对焦距离28cm，拍微距还是凑合的。EF-S 18~55mm F3.5~5.6 II USM采用外对焦设计，但得益于超声波马达的加入，对焦速度还是比较不错的，66.2×69mm的体积和190g的重量比较轻便，搭配400D这样的小机身非常合适，并且便于携带。
EF-S 18~55mm F3.5~5.6 II USM的镜片结构图 EF-S 18~55mm F3.5~5.6 II USM的MTF曲线图 下面，咱们就来看看网友是怎么拆解这款镜头的，提醒大家注意的是，我们并不知道这支镜头拆开后有没有被复原，并且这是一支坏掉的镜头。大家千万不要拿自己手中的好头开刀，万一折腾不回去了，得不偿失的。
Canon单反镜头参数非常详细的介绍 镜头份定焦头（比如：85mm）和变焦头（比如：28mm-200mm），现在普遍的都是变焦头。说镜头的好坏从专业的角度说定焦成像肯定好但不方便。非专业很少有用定焦头的。这个就不多说了。 一般的说看镜头的好坏一般就是看光圈是否恒定和焦段是否合理，比如：光圈是F/4-5.6（非恒定光圈），肯定不如F/2.8(恒定光圈)，恒定光圈是指的光圈在那你变焦的时候不会变化，比如说：你用28mm-200mm F/4-5.6的镜头，镜头焦距在28mm的时候光圈是4 当你推到200mm 的时候光圈就自动限制为5.6了，而用数值是F/2.8(恒定光圈)的镜头就不会出现这种问题，但是恒定光圈的镜头不是很多，价格很高，基本在10000左右（可以考虑二手）。再就是光圈大小也很关键，因为光圈的大小决定了相机进光量的多少，也决定了在阴暗环境下相机的快门速度，比如傍晚在房间内拍照，F/4-5.6光圈的镜头快门速度肯定要比F/2.8要慢，所以就更容易拍虚。另外一点焦段的合理性是镜头变焦段的组合，如果只是初级喜欢摄影，佳能机身也可以配腾龙的18mm-300mm，一镜走天下，除了不能拍到月亮上的嫦娥其他基本都行。如果你是发烧友或者专业从业者，对片子的质量要求比较专业则建议你选择小焦段镜头，比如说12-24 24-70 70-200 因为只有这样焦段的镜头才有恒定光圈或大光圈。在一个简单的办法，镜头的口径越粗越是好镜头，因为口径大光圈一定就大。 镜头的功能主要取决与焦段 主要分 鱼眼 14mm 大场景、创作专用，拍出来变形很厉害，鱼的眼睛看东西一样。 超广角16mm-28mm 风光摄影、场景、创作专用多少有点变形，画面涵盖范围广 广角28mm-50mm 风光摄影、场景、人像外景、创作专用变形小，50段没有变形，画面涵盖范围较广 中焦50mm-80mm 风光摄影、场景、人像、大型静物，创作专用，画面涵盖范围较小 长焦80mm-200mm 人像、静物，创作专用，可以拍到的物体比较远 超长焦400mm以上运动摄影、野外动物、创作专用，可以拍到的物体比非常远 另外还有特殊功能的镜头微距镜头主要拍昆虫、花草、小型静物如戒指等。 还有一个特殊功能的镜头是移轴镜头拍建筑专用，不过用的很少了，专业的人都用座机拍了。 佳能的镜头有很多其他的参数，什么防抖，有什么光学玻璃的，在选择的时候，不必在乎这
P：优点 C：缺点 一、单镜头的选择 1.成本最低，性价比最高 EF-S 18-55/ 只有二手的看成色￥400上下 P：广角长焦都沾上，关键是便宜好用 C：就花了这么点钱来说，没什么可说的 我常说看得起套头的人，会使用套头的人，常常让拿着数nW器材的人大吃一惊。 也可以选择低EF-S 18-55/、EF-S 18-55/ USM版。 2. 成本最低，性价比最高II EF50/ ￥750 P：成像相当不错 C：焦段严重不足，做工很差，只适合入门 不少人对50/的做工严重不屑，但使用50/的人很多对其性能价格很满意。不要以貌取镜，也不要想凭它争面子，要么它拍出的片子说话。 3.一镜足矣 EF-S 17-85/ IS USM ￥4800 P：焦段太合适了，IS用了都说好， C：性价比略低 FSLR上，EF28-135/ IS USM是非常经典的头头，价格不错、成像不错，I、U俱全。17-85作为对应的EF-S版本，虽然价格高了不少，光圈略小，但无法阻止它成为单镜头配置的好选择。 4.失去长焦，得到红圈 EF17-40/4L USM ￥6000 P：非常好的广角头，不论价格、成像还是做工。 C：缺乏长焦，遮光罩太难看。 有评测指出，17-40L在广角段成像优于昂贵的16-35L。它外形很象16-35L足够你亮骚、机械性能很好、使用和成像都让人满意。 5. 拥有=拥抱高端 EF-S 17-55mm f/ IS USM ￥8000 P：不画红圈的L头，IS、USM、恒定一样都不少 C：你真的不考虑全副了吗 Canon为了APS尺寸打造的主力镜头，性能成像没啥说的。不标L有两种可能：Canon认为L头应该是全副的；这个头毕竟是塑料的，与24-70之流还是有差距的。唯一的问题是为APS 镜头投入这么多，将来换全副相机的时候怎么办
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“CANON ZOOM LENS EF-S 10 -22mm 1：3.5-4.5 USM ”。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“18-50mm F2.8-3.5 0.5m-∝”。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