TED科普：为什么你的屏幕形状很重要？
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电视或DVD里的电影开始前，都有一条免责声明说“这部电影的内容，已经修改为适合电视荧屏播出的尺寸。”这让你以为你看到的视频是自适应的全部，实际上，你看到的视频可能只是被截取的一半画面！
You know, back in the 40s and 50s, the original standard television had a 4 to 3 width to height ratio.
你知道，上世纪四五十年代时，电视屏幕的标准长宽比本来是4：3。
That shape was chosen to be a slight rectangle, but still mostly square, thus having the maximal screen area for the given dimensions.
这个形状虽是长方形，但仍然很接近正方形，因此在给定的维度下实现的面积最大。
And that's still the ratio on many TVs and computer monitors in today's homes.
今天的许多电视电脑仍然沿用了这一比例。
The problem is, hardly anybody today treats video content in a 4 to 3 ratio.
问题是，现在几乎没人还看4：3的视频了。
See, this whole problem started when people wanted to watch movies from the theater in the comfort of their own homes.
看吧，当人们想在自己家中欣赏和在影院效果一样的电影时，问题就来了。
Movie screens are considerably larger than our home television.
银幕的尺寸比电视大得多。
More important, the screen is completely different rectangle, and can't mathematically fit on our TV screens without manipulation.
更重要的是，银幕用的是完全不同的长方形，这样的尺寸很难不经调整就直接被搬上电视屏幕。
A typical TV is one and a third times wider than it is tall. Some movie screens could be up to three times as wide as it is tall.
通常，电视屏幕的长宽比是4：3。有些电影的长度可以达到宽度的三倍。
So what're we gonna do to make it fit? Well, we have all kinds of options.
那怎样才能让它们匹配呢？唔，选择还是很多的。
Well, we could squeeze and stretch and mangle everything on to the screen, to make it all fill up, and everyone would look ridiculously thin and compressed.
我们可以压缩和拉伸，把所有内容都塞进屏幕，让屏幕被画面完全覆盖，但是画面上的人就会显得特别瘦，看起来像被压扁了一样。
The good news is the sound would be just fine.
好消息是，声音和画面还是匹配的。
Although I don't think people would be too happy about that option, particularly the actors in the movie.
不过我不知道人们会不会满足于这个方式，尤其是电影的演员们。
We could just cut a chunk of the original movie like a cookie cutter and just see that frame of the movie.
我们也可以像用模具切面片一样从原版电影中截一块，并以此作为框架。
The problem with that would be that people and objects would be speaking from off the screen, or even worse, they might be cut in half.
这么做的问题是，说话的人可能被挡在了屏幕之外，更糟的是，他们可能被切掉一半。
Some movie editors use what's called the "pan and scan" technique to allow the full height of the TV screen to be used, but pick and choose what section of the original movie should be shown on your screen thus eliminating the annoying cutting of people.
一些影片编辑使用一种叫“平移与扫描”的技术来充分使用电视屏幕的宽度，可以选择电影的哪一部分应该出现在电视屏幕上，这样就能避免经常把人像剪开了。
Imagine that job, staring at a 4 to 3 hole watching movies all day, deciding for everyone which piece of the screen is the most important part for people to see.
想像一下这份工作：从4：3孔开始，整天就看电影，并决定画面的哪一部分是观众一定要看的。
Now let's do a little quick math.
现在让我们迅速算一算。
If we compare a major cinematic film produced on a 2.35 to 1 aspect frame with my standard 4 to 3 TV screen, we find out that only 55% of the movie can actually fit on the screen at any one time.
比较一下2.35：1的银幕电影和4：3的标准电视屏幕，我们就能发现，只有55%的电影，每一幕都可以完整地搬上屏幕。
Just over half!
只有一半多一点！
You've seen the disclaimer at the beginning of the movie on TV or DVD that says "this film has been modified from its original format to fit on your TV screen."
电视或DVD里的电影开始前，都有一条免责声明说“这部电影的内容，已经修改为适合电视荧屏播出的尺寸。”
Well, what it should say is "we are only displaying 55% of the movie of our choosing."
其实，它该说的是“我们只展示了选出的55%的电影画面。”
Now for all the full-screen TV lovers, this is your dilemma: do you want to see all the movie, or is 55% good enough? How about new TVs?
对所有热爱全屏电视的人来说，这是个进退两难的局面：你想看电影的所有，还是质量好的55%那部分？那换个新电视机呢？
Around the start of the century, some widescreen TVs emerged in a 16 to 9, or 1.78 times wider than it is tall.
本世纪初，有些宽屏电视采用了16：9，也就是1.78：1的长宽比，
Well, this screen fits the movie a little better, but still only shows 75% of the original movie at one time.
这样的屏幕与电影稍微匹配了一些，但也只适合75%的原版电影。
Suppose someone made a TV for your living room that was actually 2.35 to 1 to show those full movies?
如果有人在客厅装了2.35：1的电视来放原版电影呢？
Well, the TV with the same height as the most current 50-inch TVs - that TV would be close to six feet long.
如果这电视的宽度和一般电视一样有50英寸(127cm)，那它的长度就要达到6英尺(1.83m)。
And on top of that, you'd only use the full screen when you watched movies.
关键是，你只有看电影时，才需要这么大的全屏。
Most of the other content would have to be stretched, or have empty space on the sides of the screen.
而其他画面要么会被拉伸，要么会让屏幕边缘留下黑边。
Of course, there is one more option. We can just shrink the movie screen proportionally, to fit the width of your home television.
当然，还有一个选择。我们可以按比例缩小电影画面来与电视屏幕相匹配。
Now we can mathematically scale the original to fit exactly the width of the screen and this'll preserve the entire movie screen, but show the infamous black bars along the top and bottom that so many television watchers abhor.
我们能给电影算出正好适合屏幕的长宽比，并保留电影的全部画面，但画面上下会出现难看的黑条，很不受电视观众待见。
Of course, now you can argue that we're only using 75% of that screen.
当然，你也可以说现在我们只用了屏幕的75%。
And that is where the real question is: do you want your full screen, or do you want to see the entire movie?
这才是真正的问题：你想充分利用屏幕的每一寸，还是看到完整的电影画面？
Most likely, you just need a bigger TV.
最有可能的是，你需要买一台更大的电视。
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