相机像素
Tech companies love to wave big numbers and fancy sounding words around in their ads, and camera manufacturers are no exception. Although it isn’t as bad as it was a few years ago, “megapixels” is normally their go-to buzzword. But what is a megapixel and does more really mean better? Let’s find out.
科技公司喜欢在广告中大声疾呼，听上去很漂亮，摄像机制造商也不例外。 尽管还不像几年前那么糟糕，但是“百万像素”通常是他们的流行语。 但是，什么是百万像素，并没有更多的真正含义是更好吗？ 让我们找出答案。
什么是百万像素？ (What Are Megapixels?)
On every digital camera sensor, there are tiny little “photosites”. Each of these is a sensor for a single pixel. When light hits a photosite, it determines what color that pixel should be in the resulting photo. Obviously you need lots of photosites to get a high resolution image; one million photosites will give you one million pixels—or one megapixel—in the final image. This means a 20MP photo was taken with a camera that had a sensor with twenty million photosites.
在每个数码相机传感器上，都有很小的“照相场所”。 这些都是用于单个像素的传感器。 当光线照射到photosite时，它将确定像素在最终照片中应呈现的颜色。 显然，您需要大量的photosite才能获得高分辨率的图像； 一百万个photosite将为您提供一百万像素(或一百万像素)的最终图像。 这意味着使用带有传感器的相机拍摄了20MP的照片，该传感器带有两千万个照相点。
百万像素和传感器尺寸 (Megapixels and Sensor Size)
The sensors in digital cameras come in different sizes. The sensor inside your smartphone is smaller than the sensor inside a crop sensor camera and the sensor inside a crop sensor camera is smaller again than the sensor inside a full-frame DSLR.
数码相机中的传感器尺寸不同。 智能手机内部的传感器小于作物传感器照相机内部的传感器，作物传感器照相机内部的传感器又小于全画幅数码单反相机内部的传感器 。
All three of these cameras, however, can have a 12MP sensor. What changes is the size of the photosites on the sensor. On a smartphone camera, they’re tiny, while on a full-frame camera, they’ll be much much larger. This affects the overall image quality.
但是，所有这三个相机都可以具有12MP传感器。 发生变化的是传感器上的光点大小。 在智能手机相机上，它们很小，而在全画幅相机上，它们会更大。 这会影响整体图像质量。
高百万像素的利弊 (The Pros and Cons of High Megapixels)
The size of the photosites is very important for image quality and low light performance. While the technology has come a long way over the last few years, and it’s now possible to cram more photosites than ever onto a sensor, there are pros and cons to it.
感光部位的尺寸对于图像质量和弱光性能非常重要。 在过去的几年中，这项技术取得了长足的进步，现在可以将比以往更多的photosite塞入传感器中，但它有其优点和缺点。
The more megapixels a sensor has, the bigger the image it can create. This is really useful for fashion and studio photographers who want every single detail, such as the subject’s eyelashes, as clearly as they can capture.
传感器具有的百万像素越多，它可以产生的图像就越大。 这对于时装和摄影工作室摄影师来说非常有用，他们希望每个细节都能清晰地捕捉到，例如拍摄对象的睫毛。
Higher resolution sensors also make it possible to print larger photos, although that isn’t as big a deal as it used to be. As Apple has demonstrated, you can make billboards from 12MP smartphone images.
分辨率更高的传感器还可以打印更大的照片 ，尽管这并不像以前那么重要。 正如Apple所展示的，您可以使用12MP智能手机图像制作广告牌。
A camera with a lot of megapixels is also more forgiving to use. If you stand too far back from your subject when you take the photo, you’ve more flexibility to crop in close and still have a decent size image.
具有很多百万像素的相机也更宽容地使用。 如果您在拍照时离拍摄对象太远，则可以更灵活地进行近距离裁切，并且图像尺寸仍然不错。
The downside is that, with smaller photosites, you have worse low light performance. Since sensor size doesn’t change, a 20MP and a 50MP camera will have the same amount of light to work with. The photosites on the 20MP sensor will each get about twice as much light falling on them as those in the 50MP sensor.
不利的一面是，使用较小的photosite，您的低光性能会更差。 由于传感器尺寸不变，因此20MP和50MP相机将具有相同的光量。 20MP传感器上的光点落在它们上面的光线大约是50MP传感器上的光柱的两倍。
With large images also comes large file sizes. A 20MP image shot with a DSLR will often be about 25MB; with a 50MP image, the file size more than doubles to about 60MB. This not only means you need more storage (which is cheap), but more processing power in your computer to edit them efficiently (which often isn’t cheap).
较大的图像还带有较大的文件大小。 用数码单反相机拍摄的20MP图像通常约为25MB； 使用50MP映像时，文件大小增加了一倍以上，达到60MB。 这不仅意味着您需要更多的存储空间(这是便宜的)，而且还需要计算机中更多的处理能力来有效地对其进行编辑(这通常并不便宜)。
什么是最佳景点？ (What Is the Sweet Spot?)
Right now, any modern camera has enough megapixels for almost anything you could want to do. It’s no longer the differentiator it once was and, once you get passed a certain point, other factors start to become more important.
目前，任何现代相机都具有足以完成您想做的所有事情的百万像素。 它不再是曾经的差异化因素 ，一旦您通过了某个特定点， 其他因素就开始变得越来越重要 。
Smartphones seem to have settled for around 12MP sensors over the last few years. The iPhone 7, Google Pixel, and Samsung Galaxy S8 all have sensors of about this size. This seems to be a bit of a goldilocks spot in terms of image size and low light performance for small sensors. You get an image big enough to do what you want with, and they aren’t absolutely awful in low light. Cheaper phones with lower resolution sensors, and thus larger photosites, don’t have better low light performance; they generally just have worse cameras.
在过去几年中，智能手机似乎已经安装了12MP左右的传感器。 iPhone 7，Google Pixel和三星Galaxy S8都具有大约这个尺寸的传感器。 对于小型传感器而言，在图像尺寸和弱光性能方面，这似乎有点像个金发姑娘。 您会获得足够大的图像来执行所需的操作，而在低照度下它们并不是绝对糟糕的。 带有较低分辨率传感器的廉价手机(因此具有较大的照相位置)没有更好的低照度性能； 他们通常只有较差的相机。
For crop sensor DSLRs, around 20MP is a great ballpark. Canon and Nikon offer cameras with sensors between 18MP and 24MP. That’s obviously more than big enough for almost anything, but the photosites are still large enough that the low light performance tends to be okay.
对于农作物传感器数码单反相机，大约20MP是一个不错的选择。 佳能和尼康提供的相机带有18MP至24MP之间的传感器。 显然，几乎所有东西都足够大了，但是光影站点仍然足够大，以至于微光性能似乎还可以。
Full frame DSLRs have much larger sensors so can handle more megapixels. This has led to a split in the models offered. While there are super high resolution cameras with 50MP+ sensors; these are best for specialist uses in ideal settings like fashion photography in a studio. Both Canon and Nikon seem to have settled on around 30MP as the best balance between file size and low light performance for their flagship models.
全画幅数码单反相机具有更大的传感器，因此可以处理更多的百万像素。 这导致了所提供模型的分裂。 虽然有带有50MP +传感器的超高分辨率相机； 这些特别适合在理想环境中的专业用途，例如工作室的时尚摄影。 佳能和尼康似乎都确定了30MP左右，这是其旗舰机型在文件大小和低光性能之间的最佳平衡。
Right now, buying something because it has more megapixels isn’t the best idea. Instead, try to stick to those sweet spots for the sensor in your camera. You won’t go far wrong. Stepping outside of these means you’re getting into more specialist territory and will start to see the downsides of having too many megapixels.
现在，购买具有百万像素的产品并不是最好的主意。 相反，请尝试坚持相机中传感器的最佳位置。 你不会错的。 超越这些意味着您将进入更专业的领域，并将开始看到拥有太多百万像素的弊端。
Image Credits: Torbakhopper via Flickr
图片来源： 通过Flickr的Torbakhopper
翻译自: https://www.howtogeek.com/310948/do-megapixels-matter-when-buying-a-camera/
相机像素