Confused by that digital SLR you have, and all the photography jargon that goes along with it? Take a look at some photography basics, learn how your camera works, and how that can help you take better pictures.

对您拥有的数码单反相机以及随之而来的所有摄影术语感到困惑吗？ 看看一些摄影基础知识，了解相机的工作原理，以及如何帮助您拍摄出更好的照片。

Photography has everything to do with the science of optics—how light reacts when it is refracted, bent, and captured by photosensitive materials, like photographic film or photosensors in modern digital cameras. Learn these basics of how a camera—practically any camera—works, so you can improve your photography, whether you’re using an SLR, or a cellphone camera to get the job done.

摄影与光学科学息息相关-当光被感光材料(如现代数码相机中的摄影胶片或光传感器)折射，弯曲和捕获时，光如何React。 了解相机(实际上是任何相机)如何工作的这些基础知识，以便无论您是使用SLR还是手机相机完成工作，都可以改善自己的摄影效果。

到底什么是相机？ (Just What is a Camera?)

Around 400BC to 300BC, ancient philosophers of more scientifically advanced cultures (such as China and Greece) were some of the first peoples to experiment with the camera obscura design for creating images. The idea is simple enough—set up a sufficiently dark room with only a tiny bit of light entering through a pinhole opposite a flat plane. The light travels in straight lines (this experiment was used to prove this), crosses at the pinhole, and create an image on the flat plane on the other side. The result is an upside-down version of the objects being beamed in from the opposite side of the pinhole—an incredible miracle, and an amazing scientific discovery for people that lived more than a millennium before the “middle ages.”

大约在公元前400至300年，具有科学先进文化的古代哲学家(例如中国和希腊)是最早尝试使用相机暗淡设计来创建图像的人。 这个想法很简单-设置一个足够暗的房间，只有一小部分光线通过与平面相对的针Kong进入。 光以直线传播(此实验用于证明这一点)，在针Kong处交叉，并在另一侧的平面上创建图像。 结果是从针Kong的另一侧射出的物体颠倒过来，这是一个不可思议的奇迹，而且对于在“中世纪”之前生活了一千年以上的人们来说，这是一项惊人的科学发现。

To understand modern cameras, we can start with the camera obscura, leap forward a few thousand years, and begin talking about the first pinhole cameras. These use this same simple “pinprick” of light concept, and create an image on a plane of photosensitive material—an emulsified surface that reacts chemically when struck by light. Therefore the basic idea of any camera is to gather light, and record it on some kind of photosensitive object—film, in the case of older cameras, and photo sensors, in the case of digital ones.

要了解现代相机，我们可以从暗淡的相机开始，飞跃几千年，然后开始谈论第一款针Kong相机。 这些使用相同的简单“光针刺”光概念，并在感光材料的平面上创建图像，该感光材料是一种乳化的表面，当被光照射时会发生化学React。 因此，任何照相机的基本思想都是聚集光线，并将其记录在某种光敏物体上-对于老式照相机，是胶片；而对于数字照相机，则是光电传感器。

有什么比光速快？ (Does Anything Go Faster Than the Speed of Light?)

The question posed above is sort of a trick. We know from physics that the speed of light in a vacuum is a constant, a speed limit that is impossible to pass. However, light has a funny property, compared to other particles, like neutrinos that travel at such quick speeds—it doesn’t go the same speed through every material. It slows, bends, or refracts, changing properties as it goes. The “speed of light” escaping from the center of a dense sun is agonizingly slow compared to the neutrinos that escape from them. Light may take millennia to escape a star’s core, while neutrinos created by a star react with nearly nothing, and fly through the densest matter at 186,282 miles/sec, as if it was barely even there. “That’s all well and good,” you might ask, “but what does this have to do with my camera?”

上面提出的问题有点技巧。 从物理学上我们知道真空中的光速是一个常数，这是不可能通过的速度极限。 但是，与其他粒子(例如中微子以如此快的速度传播)相比，光具有有趣的性质-并非每种材料都以相同的速度传播。 它会减慢，弯曲或折射，从而随即更改属性。 与从中子逃逸的中微子相比，从密集太阳中心逃逸的“光速”令人痛苦地缓慢。 光可能要花费数千年才能逃离恒星的核心，而恒星产生的中微子几乎什么也没有React，以186282英里/秒的速度飞过最稠密的物质，就好像它甚至在那儿一样。 您可能会问，“一切都很好，但是这与我的相机有什么关系？”

It is this same property of light to react with matter that allows us to bend, refract, and focus it using modern photographic lenses. The same basic design hasn’t changed in several years, and the same basic principles from when the first lenses were created apply now, as well.

与物质发生React的正是光的这种相同属性，使我们能够使用现代摄影镜头将其弯曲，折射和聚焦。 几年来，相同的基本设计没有改变，现在，也适用从创建第一个镜头起的相同基本原理。

焦距和聚焦 (Focal Length and Staying in Focus)

While they have become more advanced throughout the years, lenses are basically simple objects—pieces of glass that refract light and direct it toward an image plane toward the back of the camera. Depending on how the glass in the lens is shaped, the amount of distance the crisscrossing light needs to converge properly on the image plane varies. Modern lenses are measured in milimeters and refer to this amount of distance between the lens and the convergence point on the image plane.

多年来，尽管它们已经变得越来越先进，但它们基本上是简单的物体-一块玻璃，它们使光折射并将光指向相机背面的像平面。 根据透镜中玻璃的形状，纵横交错的光在像面上正确会聚所需的距离量会有所不同。 现代镜头以毫米为单位测量，是指镜头与像面上会聚点之间的距离。

Focal length also affects the kind of image your camera captures, as well. A very short focal length will allow a photographer to capture a wider field of view, while a very long focal length (say, a telephoto lens) will cut the area you’re imaging down to a much smaller window.

焦距也会影响相机拍摄的图像类型。 极短的焦距将使摄影师能够捕获更宽的视野，而极长的焦距(例如，远摄镜头)会将您要成像的区域缩小到更小的窗口。

There are three basic types of lenses for standard SLR images. They are Normal lenses, Wide-angle lenses, and Telephoto lenses. Each of these, beyond what has already been discussed here, have some other caveats that come along with their use.

用于标准SLR图像的镜头有三种基本类型。 它们是普通镜头， 广角镜头和远摄镜头。 除了此处已讨论的内容之外，这些方法中的每一种方法都伴随着一些其他注意事项。

• Wide-angle lenses have huge, 60+ degree angles of view, and are usually used for focusing on object closer to the photographer. Objects in wide angle lenses may appear distorted, as well as misrepresenting the distances between distance objects and skewing perspective at closer distances.

  广角镜具有60度以上的巨大视角，通常用于聚焦在靠近摄影师的物体上。 广角镜中的物体可能会出现变形，并且会错误地表示距离物体之间的距离以及在更近距离处倾斜透视的情况。

• Normal lenses are those that most closely represent the “natural” imaging similar to what the human eye captures. Angle of view is smaller than Wide-angle lenses, without distortion of objects, distances between objects, and perspective.

  普通镜片是最能代表人眼所捕获“自然”影像的镜片 。 视角小于广角镜，没有物体变形，物体之间的距离和视角。

• Long-focus lenses are the huge lenses you see photography aficionados lugging around, and are used to magnify objects at great distances. They have the most narrow angle of view, and are often used to create depth of field shots and shots where background images are blurred, leaving foreground objects are left sharp.

  长焦镜头是巨大的镜头，您会看到摄影爱好者四处张望，并用于远距离放大物体。 它们具有最窄的视角，通常用于创建景深镜头和背景图像模糊而使前景物体保持清晰的镜头。

Depending on the format used for photography, focal lengths for Normal, Wide-Angle, and Long-Focus lenses changes. Most ordinary digital cameras use a format similar to the 35mm film cameras, so the focal lengths of modern DSLRs are very similar to the film cameras of yesteryear (and today, for the film photography buffs).

根据用于摄影的格式，法线，广角和长焦镜头的焦距会改变。 大多数普通的数码相机都使用类似于35mm胶片相机的格式，因此现代数码单反相机的焦距与以前的胶片相机非常相似(今天，对于胶片摄影爱好者而言)。

光圈和快门速度 (Aperture and Shutter Speeds)

Since we know that light has a definite speed, only a finite amount of it is present when you take a photo, and only a fraction of that makes it through the lens to the photosensitive materials within. That amount of light is controlled by two of the major tools a photographer can adjust—the aperture and shutter speed.

由于我们知道光具有一定的速度，因此在拍摄照片时仅存在有限的速度，只有其中的一小部分会使其通过镜头到达内部的感光材料。 光线的数量由摄影师可以调节的两个主要工具控制，即光圈和快门速度。

The aperture of a camera is similar to the pupil of your eye. It is more or less a simple hole, that opens wide or closes down tightly to allow more or less light through the lens to the photo receptors. Bright, well-lit scenes need minimal light, so the aperture can be set to a larger number to allow less light through. Dimmer scenes require more light to strike the photo sensors in the camera, so the smaller number setting will allow more light through. Each setting, often referred to as f-number,  f-stop, or stop, typically allows half the amount of light as the setting before it. Depth of field also changes with the f-number settings, increasing the smaller the aperture used in the photograph.

相机的光圈类似于眼睛的瞳Kong。 它或多或少是一个简单的Kong，该Kong宽开或紧闭，以允许或多或少的光线通过透镜到达光感受器。 明亮，光线充足的场景需要的光线很少，因此可以将光圈设置为更大的数值以减少光线通过。 较暗的场景需要更多的光才能照射到相机中的光电传感器，因此较小的数字设置将允许更多的光通过。 每种设置(通常称为f值，f停止或停止)通常允许的光量是之前的设置的一半。 景深也会随着f值设置而变化，照片中使用的光圈越小，其景深就越大。

In addition to the aperture setting, the amount of time the shutter stays open (aka, shutter speed) to allow light to strike photosensitive materials can also be adjusted. Longer exposures allow in more light, particularly useful in dim lighting situations, but leaving the shutter open for extended periods of time can make huge differences in your photography. Movements as small as involuntary hand tremors can dramatically blur your images at slower shutter speeds, necessitating the use of a tripod or sturdy plane to place the camera on.

除了光圈设置外，还可以调整快门保持打开状态的时间(也称为快门速度 )，以使光线照射感光材料。 较长的曝光可以增加光线，特别是在昏暗的照明条件下很有用，但是长时间打开快门可能会给您的摄影带来巨大的变化。 较小的手部震动会在较慢的快门速度下显着模糊图像，因此必须使用三脚架或坚固的飞机来放置相机。

Used in tandem, slow shutter speeds can compensate for smaller settings in aperture, as well as large aperture openings compensating for very fast shutter speeds. Each combination can give a very different result—allowing lots of light in over time can create a very different image, compared to allowing lots of light in through a larger opening. The resulting combination of shutter speed and aperture creates an “exposure,” or the total amount of light that strikes the photosensitive materials, be they sensors or film.

缓慢使用快门速度可以补偿较小的光圈设置，以及较大的光圈开口可以补偿非常快的快门速度。 每种组合都可以产生非常不同的结果-与通过较大的开口允许大量光线进入相比，随着时间的推移允许大量光线进入可以创建非常不同的图像。 快门速度和光圈的最终组合会产生“曝光”，即撞击感光材料(无论是传感器还是胶卷)的全部光量。

Have questions or comments concerning Graphics, Photos, Filetypes, or Photoshop? Send your questions to ericgoodnight@howtogeek.com, and they may be featured in a future How-To Geek Graphics article.

对图形，照片，文件类型或Photoshop有疑问或意见吗？ 将您的问题发送到ericgoodnight@howtogeek.com ，它们可能会在以后的How-To Geek Graphics文章中介绍。

Image Credits: Photographing the Photographer, by naixn, available under Creative Commons. Camera Obscura, in public domain. Pinhole Camera (English) by Trassiorf, in public domain. Diagram of a Solar Type Star by NASA, assumed Public Domain and Fair Use. Galileo’s Teliscope by Tamasflex, available under Creative Commons. Focal Length by Henrik, available under GNU License. Konica FT-1 by Morven, avaiable under Creative Commons. Apeture diagram by Cbuckley and Dicklyon, available under Creative Commons. Ghost Bumpercar by Baccharus, available under Creative Commons. Windflower by Nevit Dilmen, available under Creative Commons.

图片来源： naixn 摄影摄影师 ，可在“ 知识共享”下找到 。 Camera Obscura，在公共领域。 Trassiorf的 Pinhole Camera(英语) ，公共领域。 NASA 的太阳型恒星图 ，假定为公共领域和合理使用。 Tamasflex 创作的 伽利略望远镜( Teliscope) ，由 创用CC提供 。 Henrik的《 焦距》 ，可根据 GNU许可获得。 Morven的 Konica FT-1 ，可在 Creative Commons下获得 。 由 Cbuckley 和 Dicklyon 创作的 情节图 ，可在 创用CC下获得 。 鬼Bumpercar通过 Baccharus ，可根据 知识共享 。 白头翁通过 Nevit Dilmen ，可根据 知识共享 。

翻译自: https://www.howtogeek.com/63409/htg-explains-cameras-lenses-and-how-photography-works/