{"slug":"ps-levels-tool","title":"一招搞定曝光调整 - PS色阶工具真好用","author":"Thomas看看世界","date":"2017-08-06","wechat":"https://mp.weixin.qq.com/s?__biz=MzI4NDA5MzE5NQ==&mid=2247485822&idx=1&sn=ee6505597c03a47d5fcf1a69cb66a680&chksm=eb81f71adcf67e0c53920d1fedb7c37187e4f5d37f644be75db07985cf67e39a3c8293491d56&scene=21#wechat_redirect","blocks":[{"t":"p","x":"有没有一个工具，可以一招搞定照片的对比度、黑场、白场、整体亮度等等曝光调整呢？","b":false,"xe":"Is there one tool that handles contrast, black point, white point, and overall brightness in a single move?"},{"t":"p","x":"有的，那就是方便又好用的PS色阶工具。今天的教程，托马斯会在几分钟内教会大家色阶的使用要点。","b":false,"xe":"Yes — the convenient and capable PS Levels tool. In today's tutorial, Thomas teaches you the essentials of Levels in just a few minutes."},{"t":"img","f":"img-02","w":1000,"h":668},{"t":"h","x":"1","xe":"1"},{"t":"h","x":"色阶工具在哪儿","xe":"Where Is the Levels Tool?"},{"t":"p","x":"和曲线、可选颜色等调整一样，色阶有两种打开方式：","b":false,"xe":"Like Curves, Selective Color, and other adjustments, Levels can be opened in two ways:"},{"t":"p","x":"第一种是直接选择要调整的图层，打开“图像-调整-色阶”面板。这样所做的调整会直接覆盖到原图层上，无法再次修改或者撤销，并不推荐。","b":false,"xe":"The first is selecting the layer and opening Image > Adjustments > Levels. Adjustments made this way overwrite the original layer directly — they can't be modified or undone later. Not recommended."},{"t":"img","f":"img-03","w":1000,"h":1262},{"t":"p","x":"更好的方法是使用调整图层。","b":false,"xe":"The better approach is an adjustment layer."},{"t":"p","x":"图层面板下方的第四个图标，包括了所有的调整图层选项。鼠标单击该图标，然后选择“色阶”，就可以新建一个色阶调整图层了。","b":false,"xe":"The fourth icon at the bottom of the Layers panel holds all the adjustment layer options. Click it and choose \"Levels\" to create a Levels adjustment layer."},{"t":"p","x":"调整图层在原图层的上方单独存在，并没有覆盖原图层数据。因此可以随时修改、删除我们的色阶调整效果，更加好用。","b":false,"xe":"An adjustment layer exists separately above the original layer without overwriting its data — you can modify or delete the Levels effect at any time. Much more usable."},{"t":"img","f":"img-04","w":1000,"h":1622},{"t":"h","x":"2","xe":"2"},{"t":"h","x":"色阶工具五大滑块","xe":"The Five Key Sliders in Levels"},{"t":"p","x":"色阶工具中的预设、通道、吸管等等功能几乎很难用到。大部分时间，我们只需要掌握，下图中红框包含的五大滑块。","b":false,"xe":"The presets, channels, eyedroppers, and other features in Levels are rarely needed. Most of the time, we only need the five sliders framed in red below."},{"t":"img","f":"img-05","w":1000,"h":830},{"t":"p","x":"色阶面板中最引人注目的就是一个巨大的直方图。","b":false,"xe":"The most striking part of the Levels panel is the huge histogram."},{"t":"p","x":"直方图反映了调整前的图像，所有像素在0到255的亮度区间的分布。（如果对直方图不太了解，请阅读文章《不懂直方图，还谈什么数码摄影》）","b":false,"xe":"The histogram shows the distribution of all the image's pixels across brightness values 0 to 255 before adjustment. (If histograms are unfamiliar, read \"If You Don't Understand Histograms, Can You Even Talk Digital Photography?\")"},{"t":"p","x":"直方图下面有三个滑块：黑色滑块、白色滑块和中灰滑块，分别对应调整照片的最暗部分、最亮部分和整体亮度。","b":false,"xe":"Below the histogram sit three sliders — black, white, and mid-grey — adjusting the photo's darkest parts, brightest parts, and overall brightness respectively."},{"t":"img","f":"img-06","w":1000,"h":659},{"t":"p","x":"下面我会以这张灰度图为例，演示色阶中各个滑块的作用。","b":false,"xe":"I'll use the grayscale chart below to demonstrate what each Levels slider does."},{"t":"p","x":"灰度图演绎了亚当斯的分区曝光理论，图片从左到右依次为纯黑，不同亮度的灰色和纯白共11个区域。","b":false,"xe":"The chart illustrates Adams's Zone System: from left to right, eleven zones run from pure black through greys of increasing brightness to pure white."},{"t":"p","x":"我在调整色阶工具的时候，大家可以很直观的看到灰度图片各个亮度区域的变化。","b":false,"xe":"As I adjust the Levels tool, you can visually watch how each brightness zone of the chart changes."},{"t":"img","f":"img-07","w":1000,"h":526},{"t":"p","x":"首先是黑色滑块。黑色滑块定义了照片的黑场位置，也就是画面中最暗的部分有多少。","b":false,"xe":"First, the black slider. It defines the photo's black point — how dark the darkest part of the image gets."},{"t":"p","x":"如果输出色阶不动，调整黑色滑块，黑色滑块左侧的亮度区域，都会变成纯黑色。而其他区域，则会不同程度的变暗。","b":false,"xe":"Leaving Output Levels untouched, moving the black slider turns every brightness zone to its left pure black, while other zones darken to varying degrees."},{"t":"p","x":"下图中我把黑色滑块右移到数值显示64的位置。意味着原图亮度小于64的深灰色区域，现在都变成了纯黑色。","b":false,"xe":"Below, I moved the black slider right to a value of 64 — meaning every area of the original darker than 64 is now pure black."},{"t":"p","x":"可以看到灰度图中，原来不同深灰的I、II、III、IV区域，现在已经变成了漆黑一块。其他灰度区域，也有所变暗。","b":false,"xe":"In the chart, zones I, II, III, and IV — formerly distinct dark greys — have merged into one pitch-black mass. The other zones have darkened somewhat too."},{"t":"img","f":"img-08","w":1000,"h":555},{"t":"p","x":"类似的，白色滑块定义了照片中的白场位置，也就是照片中最亮的部分。","b":false,"xe":"Similarly, the white slider defines the photo's white point — the brightest part of the image."},{"t":"p","x":"如果输出色阶不动，调整白色滑块，白色滑块右侧的亮度区域，都会变成亮度255的纯白色。其他区域，亮度则会不同比例的提高。","b":false,"xe":"Leaving Output Levels untouched, moving the white slider turns every zone to its right pure white at 255, while other zones brighten proportionally."},{"t":"p","x":"下图中我把白色滑块左移到数值显示165的位置。意味着原图亮度大于165的亮灰色区域，现在都变成了亮度255的纯白色。","b":false,"xe":"Below, I moved the white slider left to 165 — every area of the original brighter than 165 is now pure white at 255."},{"t":"p","x":"可以看到灰度图中，原来不同亮灰的 VIII、IX、X区域，现在已经变成了纯白一片。","b":false,"xe":"In the chart, zones VIII, IX, and X — formerly distinct light greys — are now one expanse of pure white."},{"t":"img","f":"img-09","w":1000,"h":541},{"t":"p","x":"如果同时把黑色滑块、白色滑块往中间移动，意味着照片中的纯黑、纯白区域会大大增加，增加照片的反差对比度。","b":false,"xe":"Moving both the black and white sliders toward the middle greatly increases the pure-black and pure-white areas, boosting the photo's contrast."},{"t":"img","f":"img-10","w":1000,"h":528},{"t":"p","x":"直方图中间的滑块叫中灰滑块，对应了图像中亮度值正好为128的中灰部分。","b":false,"xe":"The slider in the middle of the histogram is the mid-grey slider, corresponding to pixels at exactly 128 — middle grey."},{"t":"p","x":"中灰滑块左侧，与黑色滑块之间，也就是照片的暗部（亮度值小于128大于0）。","b":false,"xe":"Between the mid-grey slider and the black slider lies the photo's shadow range (brightness above 0, below 128)."},{"t":"p","x":"中灰滑块右侧，与白色滑块之间，则是照片的亮部。","b":false,"xe":"Between the mid-grey slider and the white slider lies the photo's highlight range."},{"t":"img","f":"img-11","w":1000,"h":543},{"t":"p","x":"如果左移中灰滑块，可以看到亮部区域大大增加，暗部区域大大减少。","b":false,"xe":"Move the mid-grey slider left, and the highlight range grows while the shadow range shrinks."},{"t":"p","x":"反映到照片中，可以看到整张照片更偏亮了。","b":false,"xe":"Reflected in the photo: the whole image becomes brighter."},{"t":"img","f":"img-12","w":1000,"h":531},{"t":"p","x":"如果右移中灰滑块，则是暗部区域扩大，亮部区域减少。可以看到照片整体更加偏暗了。","b":false,"xe":"Move the mid-grey slider right, and the shadow range expands while highlights shrink — the photo turns darker overall."},{"t":"p","x":"通过左右调整中灰滑块，我们就能改变照片的整体亮度。","b":false,"xe":"By moving the mid-grey slider left or right, we change the photo's overall brightness."},{"t":"img","f":"img-13","w":1000,"h":525},{"t":"p","x":"直方图下面还有一个叫做“输出色阶”的工具。","b":false,"xe":"Below the histogram there's another tool: \"Output Levels.\""},{"t":"p","x":"顾名思义，输出色阶控制了调整后图像的亮度范围。左边一个滑块，控制了调整后照片的亮度下限，右边一个滑块，控制了输出的亮度上限。","b":false,"xe":"As the name suggests, Output Levels controls the brightness range of the adjusted image. The left slider sets the floor — the darkest possible output — and the right slider sets the ceiling."},{"t":"p","x":"默认的输出色阶是0到255。也就是调整后的照片，最暗的部分亮度可以是0（纯黑），最亮的部分亮度可以是255（纯白）。","b":false,"xe":"The default Output Levels range is 0 to 255: after adjustment, the darkest part may be 0 (pure black) and the brightest 255 (pure white)."},{"t":"img","f":"img-14","w":1000,"h":1076},{"t":"p","x":"如果我右移下限滑块，输出色阶的下限从0变成了111。也就意味着我调整后的照片，最暗的地方，亮度也有111。","b":false,"xe":"If I move the floor slider right, the output floor rises from 0 to 111 — meaning the darkest part of my adjusted photo can be no darker than 111."},{"t":"p","x":"观察灰度照片，可以看到改变输出色阶下限后，灰度图中纯黑、深灰色的区域都被提亮了。因为照片中最暗的部分，也只能达到亮度111的灰色。","b":false,"xe":"Looking at the chart: after raising the output floor, the pure-black and dark-grey zones all brighten, because the darkest anything can be is a grey of 111."},{"t":"img","f":"img-15","w":1000,"h":525},{"t":"p","x":"如果右移输出色阶下限的同时，右移黑色滑块，会出现什么情况呢？","b":false,"xe":"What happens if we move the black slider right at the same time as the output floor?"},{"t":"p","x":"只右移黑色滑块，照片中会有更多的纯黑色，原来的I、II、III、IV都从深灰变成了一整块黑色。","b":false,"xe":"Moving only the black slider right creates more pure black — zones I, II, III, and IV all collapse from dark grey into one black mass."},{"t":"p","x":"但是现在还移动了输出色阶下限，导致画面中最暗的地方也要有111的亮度。因此I、II、III、IV作为照片中新的最暗区域，只能达到111的灰色亮度。","b":false,"xe":"But now the output floor has also moved, so the darkest point in the image must still be 111. As the photo's new darkest zones, I, II, III, and IV can only reach a grey of 111."},{"t":"img","f":"img-16","w":1000,"h":548},{"t":"p","x":"输出色阶的上限滑块，控制了调整后照片最亮的地方可以有多亮。","b":false,"xe":"The Output Levels ceiling slider controls how bright the brightest part of the adjusted photo may be."},{"t":"p","x":"如果把输出色阶上限左移到88，照片中的纯白、亮灰色都会变淡，因为照片中最亮只能到88的亮度。","b":false,"xe":"Move the ceiling left to 88, and the photo's pure whites and light greys all wash out — nothing in the photo can exceed a brightness of 88."},{"t":"img","f":"img-17","w":1000,"h":504},{"t":"h","x":"3","xe":"3"},{"t":"h","x":"色阶的实战应用","xe":"Levels in Practice"},{"t":"p","x":"下面我会以这次在巴基斯坦斯卡杜拍摄的一张照片为例，演示色阶工具的实战应用。","b":false,"xe":"Next I'll demonstrate Levels in action on a photo I shot in Skardu, Pakistan."},{"t":"p","x":"观察原图可以发现，照片整体偏亮、发灰，显得不够通透。","b":false,"xe":"Looking at the original: the photo is overall too bright and hazy — it lacks crispness."},{"t":"img","f":"img-18","w":1000,"h":664},{"t":"p","x":"新建色阶调整图层。观察直方图可以看到，直方图两侧都有一些空白，照片中最亮的地方只有250的亮度，最暗的地方也是25左右亮度的灰色，因此整体对比显得不足。","b":false,"xe":"Create a Levels adjustment layer. The histogram shows empty margins on both sides: the brightest point only reaches 250, and the darkest is a grey around 25 — hence the weak overall contrast."},{"t":"img","f":"img-19","w":1000,"h":670},{"t":"p","x":"首先右移黑色滑块，增加照片中的黑色区域，照片反差大大强化。","b":false,"xe":"First, move the black slider right to expand the black areas — contrast jumps dramatically."},{"t":"img","f":"img-20","w":1000,"h":626},{"t":"p","x":"再左移白色滑块，让照片最亮的地方变成纯白色。","b":false,"xe":"Then move the white slider left so the brightest parts turn pure white."},{"t":"img","f":"img-21","w":1000,"h":645},{"t":"p","x":"现在照片对比度比较充分了，但是整体还是偏亮。因此右移中灰滑块，压暗整张照片。","b":false,"xe":"Contrast is now sufficient, but the image is still too bright overall — so move the mid-grey slider right to darken the whole photo."},{"t":"img","f":"img-22","w":1000,"h":652},{"t":"p","x":"前面的操作大大增加了画面中的纯黑色，而纯黑的地方在沙漠中显得“特别脏”，所以我提高了输出色阶下限到7。","b":false,"xe":"The previous steps created a lot of pure black, and pure black looks \"especially dirty\" in a desert — so I raised the output floor to 7."},{"t":"p","x":"这样画面中最暗的地方不再是纯黑色，取而代之的是亮度为7的深灰色，从而让照片看起来比较干净。","b":false,"xe":"Now the darkest parts are no longer pure black but a deep grey of 7, making the photo look much cleaner."},{"t":"img","f":"img-23","w":1000,"h":653},{"t":"p","x":"通过色阶工具的简单调整，是不是马上照片感觉就不一样了呢？","b":false,"xe":"With a few simple Levels adjustments, doesn't the photo feel transformed?"},{"t":"img","f":"img-24","w":1000,"h":668},{"t":"h","x":"欢迎关注@Thomas看看世界","xe":"Follow @Thomas Chu Photo,"},{"t":"h","x":"每周学会一个摄影技能","xe":"and learn one photography skill every week."}],"titleEn":"One Move for Exposure Adjustments: The PS Levels Tool"}