{"slug":"clarity-contrast-sharpen-diff","title":"一文读懂清晰度、对比度和锐化程度的区别","author":"Thomas看看世界","date":"2017-11-26","wechat":"https://mp.weixin.qq.com/s?__biz=MzI4NDA5MzE5NQ==&mid=2247486193&idx=1&sn=c0b7e2a5dabaa0d7894605d27d17be8a&chksm=eb81f495dcf67d83ca6370565dba2fa8434e3d09dbc02cd8209e9779a8bc1debe3156d860b7d&scene=21#wechat_redirect","blocks":[{"t":"p","x":"清晰度、对比度和锐化程度的调整，是照片后期的三个重要步骤。它们容易混淆，但各自效果却并不相同。本文会帮大家从原理上理清他们的区别。","b":false,"xe":"Adjusting Clarity, Contrast and Sharpening are three important steps in post-processing. They're easily confused, but their effects are quite different. This article clarifies their differences from first principles."},{"t":"h","x":"1","xe":"1"},{"t":"h","x":"对比度","xe":"Contrast"},{"t":"p","x":"对比度是指的画面的明暗反差程度。增加对比度，画面中亮的地方会更亮，暗的地方会更暗，明暗反差增强。","b":false,"xe":"Contrast refers to the degree of brightness difference across the frame. Increasing contrast makes bright areas brighter and dark areas darker — the tonal difference grows."},{"t":"p","x":"为了更好的解释对比度、清晰度和锐度的区别，我会使用下面一张放大20倍的纹理边缘为例子。","b":false,"xe":"To better explain the difference between contrast, clarity and sharpness, I'll use the texture edge below, magnified 20×, as an example."},{"t":"img","f":"img-02","w":1000,"h":692},{"t":"p","x":"下图就是增加对比度的结果。增加对比度之后，原来的两个物体反差扩大。","b":false,"xe":"The image below shows the result of increasing contrast: the difference between the two objects expands."},{"t":"img","f":"img-03","w":1000,"h":869},{"t":"p","x":"对比度是对全局作用的，对照片整体的明暗有较大影响。比如下面这张照片：","b":false,"xe":"Contrast acts globally and greatly affects the photo's overall tonality. Take this photo for example:"},{"t":"img","f":"img-04","w":1000,"h":557},{"t":"p","x":"对比度增加之后，照片亮的地方更亮，暗的地方更暗，一下子反差就拉开了。","b":false,"xe":"After increasing contrast, bright areas get brighter and dark areas darker — the difference immediately opens up."},{"t":"img","f":"img-05","w":1000,"h":564},{"t":"h","x":"2","xe":"2"},{"t":"h","x":"清晰度","xe":"Clarity"},{"t":"p","x":"在Photoshop以及众多软件中，都提供了清晰度的调整工具。","b":false,"xe":"Photoshop and many other applications provide a Clarity adjustment tool."},{"t":"p","x":"当我们增加照片的清晰度，靠近边缘较暗的一侧会变得更暗，靠近边缘较亮的一侧会变得更亮，但这种亮度对比的变化只局限在边缘周围的部分。","b":false,"xe":"When we increase a photo's clarity, the darker side near an edge becomes darker and the brighter side becomes brighter — but this brightness-contrast change is confined to the area around the edge."},{"t":"p","x":"清晰度相当于让边缘亮的一边加上一根白色渐变条，暗的一边加上一根黑色渐变条，从而让物体轮廓和细节纹理更加清晰。","b":false,"xe":"Clarity is like adding a white gradient strip on the bright side of an edge and a black gradient strip on the dark side, making object outlines and fine textures clearer."},{"t":"img","f":"img-06","w":1000,"h":815},{"t":"p","x":"因此增加清晰度，只会增加边缘附近的反差，让物体轮廓更清晰。对照片整体的对比度，影响没有对比度滑块那么大。","b":false,"xe":"So increasing clarity only raises contrast near edges, making outlines clearer. Its effect on the photo's overall contrast is much smaller than the Contrast slider's."},{"t":"img","f":"img-07","w":1000,"h":523},{"t":"p","x":"由于清晰度相当于让边缘亮的一边加上一根白条，暗的一边加上一根黑条，所以调整清晰度滑块时一定要注意幅度，不然照片中会出现可怕的Halo（晕影）现象。比如下图，狂增清晰度后山体交界处出现极不自然的白边和黑边。","b":false,"xe":"Because clarity is like adding a white strip on the bright side and a black strip on the dark side of each edge, be careful with its amount — otherwise terrible halos appear. In the image below, wildly increasing clarity created extremely unnatural white and black fringes along the mountain borders."},{"t":"img","f":"img-08","w":1000,"h":794},{"t":"p","x":"另外清晰度比较适合结合蒙版、渐变滤镜、径向滤镜等等，只对画面中的局部应用，否则全图中会加入过量的黑色细节，黑色细节一多就会显得非常脏。","b":false,"xe":"Also, clarity is best applied locally with masks, graduated filters, radial filters and so on — otherwise the whole frame gets overloaded with black detail, which quickly looks dirty."},{"t":"p","x":"比如下图，全局提高清晰度，画面显得比较脏。","b":false,"xe":"For example, in the image below, globally raising clarity makes the scene look dirty."},{"t":"img","f":"img-09","w":1000,"h":544},{"t":"p","x":"使用蒙版让增加清晰度的图层，只在前景区域显示。也就是我们只增加了照片前景石头、冰面的清晰度。","b":false,"xe":"Using a mask, the clarity-increased layer shows only in the foreground — meaning we only raised the clarity of the foreground rocks and ice."},{"t":"img","f":"img-10","w":1000,"h":448},{"t":"p","x":"局部增加清晰度之后，前景冰面质感大大提升，但照片整体又不会显得很脏。","b":false,"xe":"After locally increasing clarity, the foreground ice texture improves dramatically without the whole photo looking dirty."},{"t":"img","f":"img-11","w":1000,"h":659},{"t":"h","x":"3","xe":"3"},{"t":"h","x":"锐化程度","xe":"Sharpness"},{"t":"p","x":"锐化类似清晰度，只作用于物体的边缘，但原理有所不同。锐化主要是通过在边缘两侧，增加黑白相间的高对比线条“隔离带”，让边缘看起来更加突出锐利。","b":false,"xe":"Sharpening is similar to clarity in acting only on object edges, but the principle differs. Sharpening works mainly by adding alternating black-and-white high-contrast 'separation lines' along both sides of an edge, making it look more pronounced and crisp."},{"t":"img","f":"img-12","w":1000,"h":810},{"t":"p","x":"Adobe Camera Raw中，锐化工具在第三个面板 － 细节面板。","b":false,"xe":"In Adobe Camera Raw, the sharpening tool lives in the third panel — the Detail panel."},{"t":"img","f":"img-13","w":955,"h":1000},{"t":"p","x":"无论哪种软件，细节面板中的锐化工具，都有四个滑块：数量、半径、细节和蒙版。他们恰好对应了锐化中存在的三大问题。","b":false,"xe":"In either application, the sharpening tool in the Detail panel has four sliders: Amount, Radius, Detail and Masking. They correspond exactly to the three major problems in sharpening."},{"t":"img","f":"img-14","w":1000,"h":683},{"t":"p","x":"以上面这张锐化过度的照片为例，三个问题分别是：","b":false,"xe":"Take the over-sharpened photo above as an example — the three problems are:"},{"t":"p","x":"1）叶片边缘锐化强度过大，显得很假。而锐化强度，是由“数量”滑块决定的。","b":false,"xe":"1) The leaf edges are sharpened too strongly and look fake. Sharpening strength is decided by the 'Amount' slider."},{"t":"p","x":"2）叶片边缘出现了明显的白边和黑边，这是因为锐化作用的区域过大，本应很细微的边缘对比，一下子成了一大条白色和黑色色块。锐化区域，是由“半径”滑块控制。","b":false,"xe":"2) Obvious white and black fringes appear along the leaf edges — the sharpened region is too wide, turning what should be a subtle edge contrast into big white and black blobs. The sharpening region is controlled by the 'Radius' slider."},{"t":"p","x":"3）水面内部本来不是边缘的区域也被锐化了，一下子多了很多噪点。而识别哪些是边缘，哪些不是边缘，由“细节”和“蒙版”滑块控制。","b":false,"xe":"3) Areas inside the water that aren't edges got sharpened too, suddenly adding lots of noise. Deciding what is and isn't an edge is controlled by the 'Detail' and 'Masking' sliders."},{"t":"h","x":"锐化数量","xe":"Sharpening Amount"},{"t":"p","x":"锐化数量决定了锐化的强度，也就是边缘的对比度，以及边缘和物体的隔离程度。下面是ACR默认的25数量时，边缘的锐化情况。","b":false,"xe":"Amount decides the sharpening strength — i.e., the edge contrast and the degree of separation between edge and object. Below is the edge at ACR's default Amount of 25."},{"t":"img","f":"img-15","w":1000,"h":692},{"t":"p","x":"一旦把锐化数量提高到150，不仅边缘深浅两种颜色的反差更大，而且还出现了多条“隔离带”，让边缘更明显了。","b":false,"xe":"Once Amount is raised to 150, not only is the contrast between the two edge tones greater, but multiple 'separation bands' appear, making the edge even more prominent."},{"t":"img","f":"img-16","w":1000,"h":828},{"t":"p","x":"在具体的照片中，我们需要根据物体的特点决定锐化数量，比如人物照片可能20、30就够了，而建筑雕塑这类超过100也不觉得过。怎么观察呢，第一步，把照片放大到100%甚至更大，这样才能清楚的看到锐化效果。","b":false,"xe":"On real photos, we decide Amount based on the subject: portraits may only need 20-30, while architecture and sculptures can exceed 100 without looking overdone. How to judge? Step one: zoom the photo to 100% or more, so you can clearly see the sharpening effect."},{"t":"img","f":"img-17","w":1000,"h":556},{"t":"p","x":"第二步，拖动数量滑块，直到物体的边缘和细节凸显出来。（拖动数量滑块的时候，同时按住Alt键，可以把照片由彩色变成黑白，更加方便观察）","b":false,"xe":"Step two: drag the Amount slider until the object's edges and details stand out. (While dragging, hold Alt to turn the photo black-and-white for easier observation.)"},{"t":"img","f":"img-18","w":1000,"h":625},{"t":"h","x":"锐化半径","xe":"Sharpening Radius"},{"t":"p","x":"锐化半径决定了锐化作用的区域，半径越大，边缘会有更多区域成为反差隔离带。比如下面这张照片，半径设为默认的1.0时，边缘被锐化的区域只有3个像素。","b":false,"xe":"Radius decides the region the sharpening acts on — the larger the radius, the more area around an edge becomes a contrast band. In the photo below, with the default Radius of 1.0, only 3 pixels along the edge are sharpened."},{"t":"img","f":"img-19","w":1000,"h":777},{"t":"p","x":"当半径增加到3.0时，边缘8-9个像素到区域都产生了锐化效果。","b":false,"xe":"When Radius increases to 3.0, the sharpened region along the edge grows to 8-9 pixels."},{"t":"p","x":"半径太大，物体边缘会有黑边白边的出现，看起来有点恐怖。","b":false,"xe":"Too large a radius creates black and white fringes around object edges — looking rather scary."},{"t":"img","f":"img-20","w":1000,"h":773},{"t":"p","x":"记住在细节面板中，键盘上的Alt键是一个非常有用的按键。在调整半径时，按住Alt键，可以看到物体边缘锐化的作用效果。","b":false,"xe":"Remember: in the Detail panel, the Alt key is extremely useful. While adjusting Radius, hold Alt to see exactly where sharpening acts along the edges."},{"t":"img","f":"img-21","w":1000,"h":915},{"t":"p","x":"按住Alt键，半径过大时，会有比较明显的黑白线条出现。一般照片，锐化半径都保持在默认的1或者更低，极少有超过1.5的情况。","b":false,"xe":"Holding Alt, an oversized radius shows obvious black and white lines. For most photos, keep Radius at the default 1 or lower — it rarely exceeds 1.5."},{"t":"img","f":"img-22","w":1000,"h":895},{"t":"h","x":"锐化细节","xe":"Sharpening Detail"},{"t":"p","x":"锐化细节就像“细节”字面本身提示的那样，这个滑块决定了多大反差的边缘才会被锐化。","b":false,"xe":"As the word suggests, the Detail slider decides how much contrast an edge must have to get sharpened."},{"t":"p","x":"当细节值很小时，表示我们不需要多少细节，只有很大很明显的边缘才会被锐化。当细节值很大时，表示我们需要很多细节，即使微小反差的边缘也会被锐化。","b":false,"xe":"A small Detail value means we want little detail — only large, obvious edges get sharpened. A large value means we want lots of detail — even low-contrast edges get sharpened."},{"t":"p","x":"同样调整细节的同时按住Alt键，会显示出一个中灰色图像，图像中50%灰的区域是不被锐化影响的细节，更深更浅的部分则是会被锐化的细节。比如这张建筑照片，按住Alt键同时细节滑到0，只有轮廓清晰的建筑边缘显示了出来。","b":false,"xe":"Likewise, hold Alt while adjusting Detail: a mid-gray image appears, where 50% gray areas are detail unaffected by sharpening, while darker and lighter parts are detail that will be sharpened. In this architecture photo, holding Alt with Detail at 0, only the crisply outlined building edges show."},{"t":"img","f":"img-23","w":1000,"h":779},{"t":"p","x":"如果我把细节值提高到26，一些更小的边缘也会被锐化。比如箭头所指的建筑墙体的花纹，在细节为0时被直接忽略了，在细节26时则会被锐化。","b":false,"xe":"If I raise Detail to 26, some smaller edges get sharpened too. For example, the patterns on the building's wall indicated by the arrow were ignored at Detail 0, but get sharpened at 26."},{"t":"img","f":"img-24","w":1000,"h":787},{"t":"p","x":"如果我进一步把细节提高到100，图像中大大小小的各种细微边缘都会被锐化，甚至纯色天空中的噪点也会被锐化，这显然不是我们想要的。一般来说，默认的25是一个对大部分照片适用的值。","b":false,"xe":"If I push Detail further to 100, all fine edges big and small get sharpened — even noise in the pure-color sky gets sharpened, which is obviously not what we want. In general, the default 25 suits most photos."},{"t":"img","f":"img-25","w":1000,"h":798},{"t":"h","x":"蒙版","xe":"Masking"},{"t":"p","x":"细节是一个加法，细节值越大，越细微的边缘也会被锐化。而蒙版则是一个减法，它会识别出照片中类似天空、水面、皮肤等大片纯色区域，让锐化不作用于这些区域。蒙版是锐化工具中，重要程度最高的一个滑块，它让我们实现了局部锐化。","b":false,"xe":"Detail is additive — the larger its value, the finer the edges that get sharpened. Masking is subtractive: it identifies large solid-color areas like sky, water and skin, and keeps sharpening away from them. Masking is the most important slider in the sharpening tool — it gives us local sharpening."},{"t":"p","x":"蒙版为0的时候，大片天空也被锐化，本来应该纯蓝一片的天空却出现了许多颗粒。","b":false,"xe":"With Masking at 0, the whole sky gets sharpened, and what should be pure blue sky shows many grainy artifacts."},{"t":"img","f":"img-26","w":1000,"h":733},{"t":"p","x":"同样按住Alt键时移动蒙版滑块，图像中会显示出蒙版的作用情况，黑色表示完全不会被锐化，白色表示该部分会被锐化。蒙版提高到25，天空中仍然有大量白色线条，那些地方会被锐化，不好！","b":false,"xe":"Likewise, hold Alt while moving the Masking slider: black means completely protected from sharpening, white means sharpened. At Masking 25, the sky still shows many white lines — those areas would be sharpened. Not good!"},{"t":"img","f":"img-27","w":1000,"h":625},{"t":"p","x":"蒙版直接升到100，天空中一片黑色，说明天空完全不会被锐化。不过这个时候建筑内部也是大片黑色，该被锐化的墙体细节没有锐化，蒙版拉的过了！","b":false,"xe":"Push Masking straight to 100: the sky turns fully black — it won't be sharpened at all. But now the building interior is also largely black — wall details that should be sharpened aren't. Masking has gone too far!"},{"t":"img","f":"img-28","w":1000,"h":625},{"t":"p","x":"对这张图而言，蒙版值在60左右时比较平衡。天空几乎一片黑色，不会被锐化。同时建筑中的纹理仍然是白色蒙版，会被锐化。","b":false,"xe":"For this image, a Masking value around 60 is balanced. The sky is almost fully black (unsharpened), while the building textures remain white (sharpened)."},{"t":"img","f":"img-29","w":1000,"h":625},{"t":"p","x":"再来看看蒙版为0和蒙版为60时，天空的“颗粒噪点”情况。左边是蒙版为0，右边蒙版拉到了60，保护纯色区域的效果立竿见影。","b":false,"xe":"Now compare the sky's 'grain noise' at Masking 0 vs 60. Left is 0, right is 60 — the protection of solid-color areas is instantly obvious."},{"t":"img","f":"img-30","w":1000,"h":677},{"t":"p","x":"思考题：","b":false,"xe":"Thought question:"},{"t":"p","x":"超大半径的锐化（比如锐化半径20个像素以上），其实际效果和提升清晰度非常相似，你能理解为什么吗？欢迎在留言区讨论。","b":false,"xe":"Sharpening with an extremely large radius (e.g. 20 pixels or more) actually produces an effect very similar to raising Clarity — can you see why? Feel free to discuss in the comments."},{"t":"h","x":"理论虽好，还需实战检验。","xe":"Theory is good, but it must be tested in practice."},{"t":"img","f":"img-31","w":720,"h":1158}],"titleEn":"Clarity vs Contrast vs Sharpening: The Differences in One Article"}