What this point illustrates is that cameras are becoming increasingly sophisticated and complex.

从这方面来看，相机逐渐变得精良与复杂了。

The average digital camera today literally has many tens of
buttons, switches, dials and menu options. The question,
then, is which of all these options do you really need to know
and understand?


现代数码相机差不多都有十几个按钮，开关，拨盘与菜单选项。问题是，所有的这些选项你真的都需要知道与理解吗？

To answer this question, let me relate a story from my childhood.
When I was a young boy, my father was a pilot in the
British Royal Air Force, flying high-level reconnaissance and
bomber planes. Every year the RAF base at which we were
stationed would hold an open day and, as the son of a pilot,
I received special privileges, one of which was the opportunity
to sit in my father’s flight seat. So, at the age of five, I
found myself perched in the cockpit of a Canberra aircraft,
surrounded by hundreds of switches, dials and buttons.


为了回答这个问题，让我先给你讲一个我童年时期的故事。当我还是一个小孩的时候，我的父亲是英国皇家空军的一名飞行员，他主要驾驶高级侦察机与轰炸机。每年RAF（皇家空军）基地都会有一天对公众开放，作为一名飞行员的儿子，我得到了一点特权，让我有机会坐在我父亲的驾驶室里。因此，当我五岁的时候，我就能坐在Canberra飞机的操控座上，围绕着我的是数以百计的开关，按钮与表盘。

Intrigued, I asked him, “Dad, how do you know what all
these switches, buttons and dials mean?”

这使我大感兴趣，我问道：“父亲，你怎么会知道这所有的开关、按钮与表盘的含义呢？”

“Well,” he replied, “it’s really quite simple. In an airplane
there are six instruments that are essential and they are the
ones sitting directly in front of you on the fl ying panel—
altimeter, air speed, vertical speed, artificial horizon, turnand-
slip indicator, and the compass. Of the others you only
really need to refer to them when they begin fl ashing. When
they flash, there’s a manual in the back of the cockpit, so you
look it up and follow any instructions the manual gives you.”


“很好”，他回答道，“其实这很简单，在飞机里其实只有六个仪表盘是常用的。它们就安放在你正前方的面板上，分别是：高度计，速度计，垂直速度，人工地平线，转向与滑行指标，指南针。其它的仪表就是给你提供一个参考而已。当另外的那些指示闪动时，在驾驶座的后面有一个操作手册，你只要查一下然后照着手册给你的指示做就可以了。”

I relate this story from my childhood because it sums up perfectly
the controls on a modern digital camera. Of the many
buttons, switches and dials, there are a few that are essential
to capturing an image—metering and exposure modes,focus, file type, white balance and ISO. The rest are nice
to have and, if shooting in JPEG mode, can be utilized in
place of postcapture processing. However, for the most part,
and particularly when shooting in RAW mode, most can be
ignored except in extraordinary circumstances. So, to begin
this section of the book, I’m going to provide an outline of
the essential camera controls—what they do and why you
need to master them.

借鉴这个我童年的这个故事，可以很好的告诉我们该如何控制一台现代数码照相机----尽管有许多的按钮、开关、与拨盘，但其实仅仅只有几个对于我们拍照来说是必要的---曝光模式、曝光尺度、焦距、文件类型、白平衡与感光度。如果是用JPEG模式拍摄，可以利用相机处理剩余的过程。然而在大多数情况下，尤其是当我们用RAW模式拍摄的情况下，剩余的设置我们几乎都可以暂时忽略。所以，在本书的开始部分，我将提供一个大纲，来列出相机的必要设置-----他们能做什么，你为什么需要掌握他们。

IMAGE FILE TYPE
文件类型


With few exceptions, digital images may be stored as JPEG
or RAW files. The option you choose will depend largely
on what you plan to do with the images once you get them
home. The general rule is that if you prefer to do little or no
postcapture processing, have no intention of ever selling your
images, and have no plans to print them much larger in size
than A4 (approximately 10  8 inches), then shoot in JPEG
mode. If, however, you enjoy the postcapture processing side
of photography, want to sell your work, and/or print them
beyond A4 size, then select RAW mode. Here are the reasons
I make this assertion.

除个别例外下，图像可以存储为JPEG或RAW文件类型。选择何种文件类型，取决于你拍摄图片后的计划。大体的规则就是：

如果你想节省力气，想省略调色过程，又没有销售你图片的意愿，也没想过要把照片打印到超过A4幅面的话。请你选择JPEG模式。

然而如果你乐于自行处理调色过程，想卖出你的作品，或是想把照片打印到超过A4幅面的相纸上。那么请你选择RAW模式。

以上就是我在抉择文件类型时所考虑的。

PHOTO © CHRIS WESTON
Printed to no more than A4 size, visually there is little obvious diff erence in quality between a high-resolution JPEG image (this page) and a high-resolution TIFF
created from a RAW file (next page).


如果并不像打印到超过A4幅面的大小，从视觉上看是很难分辨高分辨率的JPEG图像（这一页），与从RAW文件创建的高分辨率TIFF文件（下一页）之间的画质区别在哪里的。

JPEGs: The Good, the Bad, and the Ugly

JPEG的优缺点

When a digital image is saved as a JPEG file, four things
happen:

当我们选择JPEG作为图像保存模式时，有以下四件事情会发生：

1.
The camera processes the RAW data, based on the image optimization settings, using built-in image processing software.

1.相机根据内建的图像处理软件根据标准设置来自动处理RAW数据。

2.
Color information is compressed from the original 12-or 14-bit (tens or hundreds of billions of shades) range
captured by the camera into an 8-bit (approximately 16.7
million shades) range.


2.色彩信息从标准的12或14位色域（几十或上千亿的色彩范围）变成8位色域（大约16.7万的色彩范围）。

3.The processed image data is compressed to reduce the file size, using a technique known as “lossy” compression.

3.图像通过一种“有损”的压缩方式缩小了文件体积。

4.
The processed, compressed file is saved to the memory device.

4.自动处理并压缩后的文件保存到了记忆卡中。

学习了！

There are two main advantages to these actions. First,
because the file is processed in-camera, the image can be printed with very little or no additional external computer
(e.g. Photoshop) processing. In other words, JPEGs are the
digital equivalent of Polaroid instant film. Second, because
the image data is compressed so that file sizes are reduced,
a memory device is able to hold a greater number of images,
compared to larger RAW (or TIFF) files.

这样做的话，有两种优点，首先，因为文件处理进程是在相机内完成的。图像完全不需要而外的电脑程序（比如PS）来处理。换句话说，JPEG图像就是数字式的拍立得一次成像。其次，因为图像数据是被压缩的，因此文件体积被大大减小了，相比RAW数据格式而言，存储设备就可以存下更多数量的图像。


However, there are disadvantages to these actions as well.
Most importantly, the processing software in digital cameras
is relatively basic and lacks the processing finesse of much
more sophisticated software solutions such as Photoshop.
Simply, you will get far better image quality if you process
the image file using better software than the camera
provides.

然而，这样也有很多缺点。最重要的是数码相机内建的图像处理软件，相对复杂的图像处理软件（如PS）而言，就来得简单与乏力多了。你只要用了更好的图像处理软件（相对相机内建的图像处理软件而言），你就可以很轻松的得到更高质量的图像。

Second, if you make an error when setting any of the image
optimization settings (or when setting white balance), it is a
complicated and sometimes impossible task to fix the error.
At the very least, it means having to spend a lot of time in
front of a computer trying to unscramble the proverbial
scrambled egg, which somewhat defeats the objective.

第二，如果当你设置了错误的图像设置（比如白平衡设置错误），修复起来的话就会变得相当复杂有时甚至是不可能完成的。或者你将在电脑前花费大量的时间根据主观臆想来修复，而这通常又都会违背客观事实。


Third, the means by which JPEG files are compressed results
in actual data being discarded permanently. As a result,
image quality will be degraded to some extent, even if it isn’t
immediately obvious or even apparent in a small-size print.
Furthermore, every time a JPEG image file is processed and
re-saved in the JPEG format, the same lossy JPEG algorithms
are applied, compounding the issue.

第三，压缩的JPEG文件格式将永久丢失一部分图像信息，因此，图像质量将退化到一定程度，即使在小尺寸打印中并不是很明显。此外，每一次JPEG图像文件的处理与重新保存，都是按照有损JPEG算法来应用的，因此加剧了问题的严重性。

Finally, an 8-bit file contains only 256 levels (tones), compared
to the 4,096 or 65,536 in a 12-bit or 16-bit file, respectively.
This may result in artifacts and banding appearing in
JPEG images that are heavily processed.

最后，8位的文件（JPEG）仅仅包含256级色调。相比12位或者16位的文件所包含的4096或65536级色调而言，JPEG图像的压缩效应是相当严重的。

RAW Files

RAW 文件格式

All of the disadvantages discussed previously are overcome when images are recorded in RAW mode. In RAW mode,the image data is saved unprocessed, that is, in its original form. While this means that the data must be computerprocessed,the advantage is that software with greater functionality,such as Photoshop, can be used to do it, optimizing image quality.

当图像以RAW格式来记录的时候，上述的所有缺陷都可以解决了。在RAW模式下，图像数据被完整保留了。但同时这也意味着数据必须通过电脑来处理，这样做带来的优点就是可以通过功能强大的软件程序（如PS）来设置图像品质。

Further, because the data is recorded in the RAW state,
image optimization settings applied in-camera can be discarded
and reapplied during computer processing, making it
possible to correct some user errors without degrading image
quality. Further still, a RAW file is like having an endless
supply of exposed but unprocessed film, which can be processed
any number of times and in any manner of different
ways without losing the ability to return to the original and start over. Not only does this enable processing of images in
different ways for different effects, it also means that when
new software technology becomes available, older images can
be reprocessed with the latest technology.

此外，因为数据以RAW状态记录，取消了相机内建图像处理程序对图像的默认设置。改由计算机来处理这一过程，这样就可以无损修复用户的某些错误设置。此外，拥有了RAW文件就像是拿到了胶片的母版，这样，我们就可以任意多次地用不同方法来处理图像，而不会因此丢失数据。不仅是可以通过不同的方式得到不同的效果，这也同样意味着如果软件技术如果得到了发展，老旧图像也可以通过最新的科技来重新解读。

Finally, because RAW image data is stored in an uncompressed
state, no data is discarded. (Some cameras provide
a RAW compression option, which roughly halves file size.However, RAW compression uses reversible (or loss-less)
algorithms, meaning that no data is discarded.)

最后，因为RAW图像数据是无压缩的状态，所以数据是无损的。（有些相机也提供RAW压缩选项，一般可以将文件体积减半，压缩RAW过程使用了无损或低损模式，也就是说几乎没有数据丢失。）
========

PHOTO © CHRIS WESTON
Close up, the effects of high levels of compression of JPEG images begin to tell.

离近了看，高等级的JPEG图像压缩效应还是比较明显的。

楼主辛苦 仔细啊

RAW  JPEG Mode

RAW+JPEG 模式
Many current DSLR (digital single-lens reflex) cameras enable image
files to be saved in both RAW and JPEG format simultaneously.

现代许多DSLR（数码单镜头反光相机）相机可以同时以RAW与JPEG模式保存图像。

This is primarily a commercial tool, allowing photographers in the field to
transmit images wirelessly to a remote site for instant upload to the
Web via the Internet (the small-size JPEG), while maintaining a highquality
RAW file for other uses, such as submission to a photo library.

这主要是一种商业工具，即允许摄影师通过现场的无线传输，即时地通过无线方式将图片上传到互联网上（小尺寸的JPEG），同时保存高质量的RAW文件另作他用，就像提交图片到图片库一样。

This option can be applied, however, in noncommercial ways. For
example, when starting out in digital photography and before the
user has the requisite knowledge of image processing software, by
selecting RAW  JPEG, an immediately usable file (JPEG) can be created
while the RAW file is stored until such time that the user feels
comfortable with computer processing techniques using Photoshop
(or any similar package).

当然，在非商业运用中，这种方式也可以被应用。举例来说，当摄影师还不具备使用图像处理软件来处理图像的时候，选择RAW+JPEG图像保存模式，既可以使用JPEG这种即时可用的图像，也可以保存RAW原始图像，以备将来具备了处理能力时重新处理图像。

A less commercial use of this function is as a back-up. If the RAW
or JPEG file becomes corrupted, the other may still be useable. Of
course, if it’s the RAW file that is corrupted, you won’t be able to
create a RAW copy from the JPEG file. However, something is better
than nothing.

一种较为少见的商业应用方式是为做备份处理。如果RAW或JPEG文件其中一种文件被损坏，那么另外一种仍旧可用。当然如果RAW文件被损坏了，你就不可能再从JPEG文件创建出一个RAW文件了。当然，聊胜于无嘛。


WHITE BALANCE

白平衡
Although we can’t see it, light at different times of the day
(e.g., sunrise and noon), under different weather conditions
(e.g., cloudy vs. sunny), and from different sources (e.g., natural
daylight and continuous-source studio lighting) varies in
color.

尽管我们有时难以分辨，光线却在一天中的不同时刻变化着（比如日出和正午）。在不同的天气状况下变化着（比如阴天与晴天），或者在不同的光源下变化着（比如自然光与棚拍光源）颜色。

The technical term for the color of light is color temperature,
and it is measured in degrees Kelvin.

描述光线的色彩的专业术语是“色温”，它是以开尔文为单位而评价的。
Humans perceive all light to be neutral white, irrespective of
its source, time of day or conditions. This is because we have
a built-in white balance (WB) control in our brain.


人类能够将所有的光线感知为中性灰，无论光源如何，无论是处在一天中的何时与何种状态。这是因为在我们的大脑中有一套内建的白平衡控制系统。

In technical terms, the purpose of the WB control in your camera is
to operate in the same way as the WB control in your head,
that is, to record all light as neutral white light.

从专业术语上来讲，你相机控制白平衡的方式与你大脑控制白平衡的方式是相同的。即将所有的光线看做是中性灰的光线。

However, there are numerous occasions when light benefits
from a color cast. For example, humans respond positively to
warm colors and to warm light, such as the light prevalent
at sunrise and sunset. Imagine a sunset without the beautiful
red glow—it’s just not the same. Yet this is exactly what the
camera is trying to achieve when WB is set to auto.
White balance can be used then to creatively enhance or
introduce color casts, in much the same way that optical filters
(e.g., 81-series “warm” filters) are used for the same purpose.
Applying WB creatively is discussed in detail in Habit 4.


然而，在有些场合下偏色会更加有益。举例来说，人类会对暖色调与暖光源有积极的反应，譬如日升日落。想象一下如果夕阳没有那种瑰丽的红色--那恐怕将于我们肉眼所见会大大不同吧，但如果你将相机的白平衡设置为自动，那么夕阳的红色就会被相机设置所削弱。

白平衡设置可以增强或减弱色温，基本上和光学滤镜的作用是相同的（譬如81系列的暖色滤镜），白平衡的具体应用将在“习惯4”中讨论。

Meanwhile, consider that setting the camera to auto WB
mode may not achieve aesthetically pleasing results.
Also consider that WB settings can be easily changed after
the fact when using RAW capture. If using JPEG, the camera’s
setting at the time of capture is used to generate the fi le
and cannot be altered easily afterward.

同时，将相机设置为自动白平衡模式可能会达不到理想的效果。

如果我们使用RAW模式拍照，改变白平衡将是很容易的事情，如果用JPEG模式拍摄，在拍照的同时白平衡就已确定，后期想改也是很难的。

ISO (AMPLIFICATION)
In digital photography, ISO relates to the extent to which
the light signal received by the sensor is amplifi ed to make
it stronger. Th e higher the ISO rating, the greater the
level of amplifi cation applied and the less signal (light) is
needed to create a workable exposure.

ISO ( 信号放大器)

在数码摄影中，ISO 是指放大传感器接收的光信号的能力。更高的ISO设置意味着可以在弱光的情况下，也可以满足曝光要求。举例来说在理想的光线条件下，ISO可以设置为一个较低的值。然而在场景昏暗的条件下就需要更高的ISO值。

bright conditions where light is plentiful, ISO may be set to
a low value (e.g., 100). However, in dim lighting a faster ISO
might be needed in order to achieve an adequate exposure
value.

In effect, this makes digital ISO much the same as film ISO.
However, the fact that digital cameras use amplification
makes the process of digital ISO very different from that
of film (which uses an increase in the physical size of the silver halide crystals to aff ect sensitivity). The role of ISO and
the effects of increases in ISO rating are covered in detail in
Habit 4. At this stage, it is simply important to understand
two main facets of this camera control:
The higher the ISO rating, the less signal (light) is needed
to create an exposure.
1.
Th e higher the ISO rating, the greater the possibility of
noise adversely aff ecting image quality.




从效果上来说，数码摄影中的ISO与胶片的ISO作用是一样的。但是，数码相机是利用信号放大器来控制ISO的，这又与胶片大不相同（胶片是使用增大银盐体积的方式来增强光线敏感度的）。

由于数码相机与胶片相机ISO原理的不同，从而在细节上导致的区别将在习惯4中详细讨论。

在这一节，我们先简单了解一下在相机控制中，我们要注意的最重要的两点：

1.高ISO值可以让弱光满足曝光条件。

2.高ISO值会大大增加噪音（噪点），从而降低图像质量。

=========

The golden colors of early morning light are diminished when the camera is set to auto WB (page 39). Using the WB control in the same way as one might use optical
filters, in this case adding the equivalent of a warming filter by setting WB to the pre-set shade setting, will result in more aesthetically pleasing results (above).

黎明金色的阳光被相机的自动白平衡大大削弱了，如果我们对白平衡加以控制，就可以达到光学滤镜一样的效果，在此例中我们通过设置白平衡为阴影模式来增强画面的暖调。

这样，图像的效果看起来就理想多了。

Metering Mode
Th e tool used to measure the intensity of light, in order that
photographers can set an appropriate exposure, is the light
meter. In DSLR cameras this meter usually takes the form of a TTL (through the lens) refl ected light meter that is incorporated
in the camera and measures light passing through
the lens.
Most cameras today have three main metering modes, each
of which calculates exposure in a slightly diff erent way.


测光模式

为了能够满足合适的曝光，我们将度量光线强度的工具称为：测光

在单反相机中通常采取TTL（through the lens 透过镜头）方式来测量透过镜头的光线。

现代大多数相机主要有以下三种测光模式，每一种测光模式略有不同。

Multisegment Metering
The most commonly used metering mode is multisegment
metering. Canon refers to this mode as evaluative metering;
other manufacturers, including Nikon, call it matrix metering;
Sony/Minolta uses the term honeycomb metering; and
still others refer to the simple term “multisegment” only.
It is a highly accurate form of metering when the subject
brightness range (i.e., the diff erence between the darkest and
brightest areas, also referred to as the scene’s dynamic range)
falls within the dynamic range limits the sensor is capable of
capturing, and when an exposure is required that faithfully
reproduces the scene as we experience it. Th e system works by
taking several separate meter readings from various areas of
the frame and then assessing them collaboratively in order to produce an exposure value (EV) that will create an image with
a full tonal range (or as close to it as the sensor is capable of ).


测光模式

为了能够满足合适的曝光，我们将度量光线强度的工具称为：测光

在单反相机中通常采取TTL（through the lens 透过镜头）方式来测量透过镜头的光线。

现代大多数相机主要有以下三种测光模式，每一种测光模式略有不同。

多重测光

最常用的测光模式为多重测光，佳能相机称之为评价测光。其它的品牌，包括尼康，则称之为矩阵测光。

索尼/美能达 称之为蜂窝式测光（？），其它的一些品牌则通称为“多重测光”。

通常这种测光模式在物体的亮度范围（例如亮部与暗部的区别，也称场景的动态范围）与传感器的动态范围能力较为接近的时候，测光的结果都是很准确的，可以较为忠实地反映场景。

该系统的工作原理是从各分区的几个独立的光度读数，来综合评估，从而以产生一个曝光值（EV），并以此为依据，来表现画面的所有明暗细节（或者一个与传感器动态范围接近的结果）。







================
The disadvantage of high ISO ratings can be seen in this image of a puma. Note
the high level of noise that can be seen, particularly in the shadow areas of the
chest and belly.

高ISO值的缺点可以从这张美洲狮的图片中清晰的看到，尤其是在胸腹部的阴影区域，噪点尤为明显。


=============
Multisegment metering mode is ideal for general shooting conditions, when
scene dynamic range doesn’t exceed camera dynamic range.

当场景的动态范围不超过相机的动态范围时，多重测光模式是可以达到理想效果的。

楼主很强！！！非常感谢！既学习了摄影知识也对照学习了英语。