二、 佳能CANON
USM（U） ULTRASONIC MOTOR 1987年佳能首创并率先使用专利核心技术的超声波马达来装备到EF镜头内，这类无齿环形直驱马达，具有低转速和高扭力，静音和体积纤巧的特点。由于超声波的振动，构成旋转式的推动力，通过环形弹簧的压力，振动部件触动旋转的配件，使动作轻快而宁静，从而使自动对焦加快、精确和接近无声。这种超声波环形马达，适合大光圈和超远摄影镜头采用。采用超声波马达，还可获得全时手动功能，启动AF自动对焦进行当中，使用者可随时按需旋动对焦环，用手动方式对焦距进行精确修正，不必拨动AF/MF转换到手动（MF）档，能配合热衷于手动对焦的拥护快速进行手动对焦。缩短对焦时间。当佳能USM专利超过十年保护期之后，采用该项目相似技术的陆续有适马HSM、尼康SWM、美能达SSM和康泰时645机的蔡司镜头。
MICRO USM MICRO ULTRASONIC MOTOR 微型超声波马达是USM马达的革新产品，采用更精密的圆桶型取代普通的环形设计，使体积和重量减少了50%，成本降低到1/30，有利于未来更多EF镜头面世。目前众多EF镜头采用后，操作时噪声减少了4倍，对焦速度提高50%，但体积和重量不变。
AFD ARC FORM DRIVE 弧型超声波马达，工作原理与微型超声波马达一样，只是外形，体积和重量不通，但在机身上无特别标注。例如EF20-35/2.8了、EF100-300/5.6L等8种
DC DIRECT CORELESS MOTOR 直流无轴马达，代替USM超声波马达驱动镜片组进行自动对焦和变焦。例如近期推出的EF28-90MM F4.6-5.6装有DC马达
IS IMAGE STABILIZATION IS是光学防抖动影像稳定器，于1995年面世，曾获欧洲摄影器材大奖。原理是由内置小型震动感应器检测出震动次数、角度转化为电子消魂好，内藏影像稳定光学镜头组根据16比特微处理器发出的指令做出偏移将光轴稳定住，补偿在手持拍摄时因轻微晃动也不会造成影响模糊。允许比正常快门速度降低两档，新款的可降低三档，仍能获得相同清晰度
PC PERSPECTIVE CONTROL 透视调整专用TS-E型摄影镜头，镜头可以作倾角及偏移的改动，令摄影的范围更广阔，即使用最大光圈，也能获得广阔的景深。1、倾角纠正：调整倾角可更改镜头及胶片平面的焦点平面角度改变镜身中间部分倾斜，将倾角改变，使拍摄平面和胶片平面一致。2、偏移矫正：调整偏移（平移）可更改镜头的光轴，获取透视的准确性
TS-E TS-E与PC同义。有广角24MM，标准45MM和90MM
SIC 超级凸轮系统，在内后对焦的镜头里，根据变焦距离用六组焦进行高精度修正，常用于5倍以上变焦镜头。
/ COMPACT-MACRO 精密级微距镜头。
/ LIFE SIZE CONVERTER EF 供EF 50MM F2.5 MARCO专用增距器，接入后从原来半原大（0.5X）倍增至（1.0X）一比一。
13.gt镜头
gt镜头是指美能达独特设计的多片多组配合巧妙的镜头组件，镜头镜片使用高档低色散光学玻璃，其中包含多枚模铸成型非球面镜片等等。也就是说美能达的 g 系列高档专业传统相机（银盐相机）使用的镜头称为af镜头，而美能达将生产 g 系列镜头的工艺技术应用于数码相机的设计生产中，所生产出的产品就称为 gt 镜头。
65.镜头的mtf
镜头的mtf是反映镜头成像质量的一个测试参数和镜头对现实世界的再现能力，mtf的英文全称是modular transfer function。镜头的mtf虽被除几个镜头生产商所采纳，但并不是国际标准。由于数码相机是光电一体化的产品，尤其是非专业机型，镜头是不可更换的，成像不仅反映了镜头的成像性能，而mtf只是反映镜头成像质量好坏的参数之一。
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备份
Behold, the bus of the future
IT LOOKS rather like a futuristic stretch limousine, but its actual function is rather more populist: the Superbus is a novel public-transport system being developed in the Netherlands by the Delft University of Technology. It is an electric bus designed to be able to switch seamlessly between ordinary roads and dedicated “supertracks”, on which it can reach speeds of 250kph (155mph). It could thus present an alternative to much more expensive magnetic-levitation trains. The Superbus would be driven in the usual way on roads and an autopilot would be engaged when it reached a supertrack.
Though it is as wide and long as a standard city bus, the Superbus is only 1.7 metres high, or roughly the same height as a sports-utility vehicle. Joris Melkert, the project's manager, explains that the designers managed to keep the Superbus this small by doing away with the central aisle usually found in today's buses, a vestigial design feature that allows passengers to stand upright, but also gives conventional buses the aerodynamic profile of a brick.
The low-riding Superbus, in contrast, has a separate door for each of its 30-odd seats. The low ceiling and the use of lightweight materials make for a far more streamlined vehicle, which in turn requires only a modest electric motor: though engineers have not yet decided whether the Superbus will be powered by fuel cells or batteries, they estimate that it will be able to accelerate from rest to 100kph in a leisurely 36 seconds.
The individual doors also allow for rapid loading and unloading of passengers, which will need to be fast if the Superbus is to live up to its promised door-to-door mission: instead of making predetermined stops, the vehicle will pick up and drop off passengers based on their text-messaged requests. This kind of flexibility is a central tenet of the project; the estimated three-year lifespan of a Superbus (as opposed to thirteen years for a standard European bus) will also allow the latest technologies to be phased in quickly as they become available.
To start with, that might include satellite-based tracking to keep the Superbus on course, sensors to scan the road for obstacles up to 300 metres ahead and a smart suspension system that remembers the rough spots in the road. The special supertracks, too, will form a technological testing ground, storing solar energy in the summer and using it in the winter to heat up the lanes and prevent them from freezing and cracking.
Conveniently enough, much of the technology comes from Delft University itself, which houses one of the world's largest aerospace-engineering departments. (The headquarters of the European Space Agency are located in nearby Noordwijk.) The university's industrial-design department has cooked up the Batmobile-like blueprint for the prototype; the project's chief designer, Antonia Terzi, previously worked on Formula 1 cars for Ferrari and Williams-BMW.
Some detractors have suggested that making so many stops would erode the Superbus's speed advantage, and others question whether a new cog in the Netherlands' already-intricate transport infrastructure is even needed. Furthermore, the Superbus does not yet exist, whereas maglev trains are already operating successfully in Shanghai.
The future of the project is uncertain. Its intended route, a new transport link connecting Amsterdam with the northern city of Groningen, was recently scrapped by the Dutch government (although the Superbus was deemed the most feasible of all the options considered, which also included a maglev train). In spite of the setback, the project has since received an extra 7m ($9m) in government funding, plus 1m from Connexxion, a local bus company. The Superbus team's latest plan is to unveil a fully functional prototype at the Beijing Olympics in 2008. With its combination of low emissions, high speed and snazzy design, this might prove to be a bus that is worth waiting for.
