现在，越来越多的Apple设备在其描述或名称中包含“Retina”或“ Retina Display ”一词。(Retina Display)但什么是Retina显示屏？如果可以选择，您是否应该选择Apple设备的(Apple)Retina版本？
很快，你可能别无选择，因为Apple全面支持Retina，但即便如此，了解他们时髦的品牌名称背后的真正含义也很重要。
Retina显示器本质上是高质量的显示器。Apple认为它们与非Retina屏幕相比有了(Retina)很大(Apple)进步，它应该有一个商标名称。那么究竟是什么大惊小怪呢？
什么是视网膜显示器？
要了解为什么它们被称为“视网膜”显示器，了解这个词的含义会很有帮助！简而言之，视网膜是眼睛解剖结构的一部分。如果您想将其与数码相机进行比较，它本质上就是眼睛的图像传感器。
眼睛的晶状体将光线聚焦到视网膜上，形成图像。构成视网膜的光敏细胞使用视神经传递这些信息，然后由大脑的视觉皮层接收并进行处理。
这与Apple的Retina显示器有什么关系？苹果(Apple)之所以选择这个名字，是因为他们认为人眼在正常使用时是看不到Retina显示屏的像素网格的。承认这些显示器是为了响应人类感知而创建的，而不仅仅是追求更高规格的追求。
都是关于像素的
关于Retina(Retina)显示器，需要意识到的重要一点是，该术语并不指任何特定的显示技术。Apple目前拥有LED、LCD和OLED显示器，均以Retina商标出售。这些屏幕不共享任何其他属性，例如分辨率、形状、大小、色彩再现或对比度。它们只是具有超过一定密度阈值的像素。
如果您不知道，像素是“图片元素”。它们是数字图像可以分解成的最小部分。每个像素都有子像素元素，可以显示不同数量的红、蓝和绿光，有效地让每个像素再现任何颜色。
当您在网格中放置像素时，您可以通过准确地告诉每个像素其颜色和亮度值应该是什么来生成图像。显示器离眼睛越近，像素网格本身就越明显。这就像看报纸照片太近了。图片分解成单独的墨点。
对于非 Retina 显示器，您不必特别靠近屏幕即可看到像素网格。它们具有明显的颗粒感，与Retina面板并排时尤其明显。那么Retina显示屏是如何实现这种锐利、无缝的外观的呢？
像素密度(Pixel Density)和观看距离是(Viewing Distance Are)关键数字(Key Numbers)
要获得“Retina”显示屏的资格，屏幕在正常观看距离必须没有可辨别的单个像素。所以，这里涉及到两个数字。
第一个是PPI或每英寸像素(Pixels Per Inch)数。这是像素密度的度量。你可以挤进每一英寸屏幕的像素越多，它们就越紧密地排列在一起，每个像素就越不显眼。
第二个数字是典型的观看距离。要成为Retina显示器，单个像素需要在典型的观看距离内肉眼不可见。对于智能手机或平板电脑设备，这些数字组合在距离您脸部 10 到 12 英寸处似乎约为 300PPI。
正如您可能已经意识到的那样，第三个数字必须是视网膜方程式的一部分：显示尺寸。
虽然您可能将平板电脑或手机放在一臂之遥，但笔记本电脑或台式机显示器通常比这更远。部分原因是设备的外形尺寸，但主要是因为这些显示器太大而无法在距离您脸部 10 英寸的地方舒适地观看。当我们看到电视时，像素密度可能远低于 300PPI，但仍算作“视网膜”，因为您通常在 6 英尺或更远的地方观看它们。
如果您想知道非 Apple 设备上的给定显示器是否符合Retina品牌的资格，您可以使用在线计算器(online calculator)来获得准确的想法。
Retina 显示器需要更改软件(Retina Displays Require Software Changes)
即使是Retina显示屏也无法将细节添加到一开始就不存在的图像中。如果屏幕上的图像具有比显示器本身更低的分辨率，那么真实的物理像素本质上会组合成更大的虚拟像素来显示图像。它实际上是数字变焦(digital zoom)的一种形式，并且可以根据视差的大小看起来像素化。
虽然对于网站等上的低分辨率图像您无能为力，但真正的问题来自文本和图标等系统元素。如果它们必须被放大，它们最终看起来非常厚实。例如， Retina(A Retina) iPhone 的像素密度是非 Retina 前辈的四倍。
这意味着 iOS 需要以四倍的细节级别显示资产才能真正利用高分辨率显示。这需要额外的计算能力和内存。好消息是，Apple Silicon具有令人难以置信的能效和强大的马力，所以这不是什么大问题。
应用程序开发人员必须注意Retina分辨率及其应用程序的外观。视频(Video)游戏尤其不能希望以原生Retina分辨率渲染图像并保持可玩性。因此，开发人员必须使用放大技巧来防止最终图像看起来块状或模糊。
视网膜是要走的路吗？
并排(Side-by-side)显示，Retina显示屏明显优于像素密度较低的显示屏。然而，高像素密度设备有很多缺点。一方面，它们要贵得多！具有如此高分辨率的 设备的电池寿命可能会更短，并且会影响上述性能。(Devices)
Apple在平衡Retina分辨率与所有这些其他因素方面做得很好，但不要认为Apple是唯一实现这些分辨率的公司。许多其他旗舰（现在是中档）设备的像素密度接近或高于 300PPI。有时没有相当于苹果(Apple)的谨慎平衡行为。
例如，一些三星 Galaxy(Samsung Galaxy)旗舰手机为用户提供了以低于屏幕分辨率的分辨率运行实际图像的选项。只有他们的最新型号才能以高刷新率显示全分辨率图像，同时仍能获得足够的电池寿命。较旧的手机只能同时提供其中两个选项。
尤其是Retina(Retina)显示屏平板电脑非常适合阅读高分辨率图画小说和漫画书，当然，也适合处理高品质照片。在手机上，它们的主要优势就是非常赏心悦目。图像出现在玻璃上，而不是略微模糊的数字投影。
最终，视网膜级像素密度将成为所有设备和所有品牌的标准。但是，如果您想在今天体验像素完美的未来，Retina显示屏是一个不错的选择。
What Is a Retina Display: Everything You Need to Know
A growing number of Apple dеνіces now have the word “Retina” or “Retina Display” included in their description or name. But what is a Retina display? Should you go for the Retina version of an Apple device if given the choice?
Soon, you might not have a choice, as Apple goes full Retina, but even then it’s important to understand what’s actually behind their snappy brand name.
Retina displays are essentially high quality displays. Ones that Apple felt are such a step up from their non-Retina screens, it deserved a trademarked name. So what’s all the fuss actually about?
What Is a Retina Display?
To understand why they’re called “Retina” displays, it’s helpful to understand what the word means! In short, the retina is a part of your eye’s anatomy. It’s essentially the image sensor of the eye, if you want to compare it to a digital camera.
The lens of the eye focuses light onto the retina, forming an image. The light-sensitive cells that make up the retina pass along that information using the optic nerve, where it’s received by the visual cortex of the brain for processing.
What does this have to do with Apple’s Retina displays? The reason Apple chose this name is because they believe that the human eye can’t see the pixel grid of a Retina display during normal use. It’s an acknowledgement that these displays have been created in response to human perception, rather than simply a quest to chase higher specifications.
It’s All About Pixels
The important thing to realize about Retina displays is that the term doesn’t refer to any particular display technology. Apple currently has both LED, LCD and OLED displays that are both sold under the Retina trademark. These screens don’t share any other attribute such as resolution, shape, size, color reproduction or contrast ratio. They just have pixels that are over a certain density threshold.
Pixels, in case you didn’t know, are “picture elements”. They are the smallest part that a digital image can be broken up into. Each pixel has sub-pixel elements that let it show varying amounts of red, blue and green light, effectively letting each pixel reproduce any color.
When you lay pixels out in a grid, you can produce images by telling each pixel exactly what its color and brightness value should be. The closer you put a display to your eye, the more obvious the pixel grid itself becomes. It’s like looking at a newspaper photo too closely. The picture breaks up into individual ink dots.
When it comes to non-retina displays, you don’t have to be especially close to the screen to see the grid of pixels.There’s a distinct graininess to them that’s especially apparent side-by-side with a Retina panel. So how do Retina displays achieve that sharp, seamless look?
Pixel Density and Viewing Distance Are the Key Numbers
To qualify as a “Retina” display, the screen must have no discernable individual pixels at normal viewing distances. So, there are two numbers involved here.
The first is PPI or Pixels Per Inch. This is a measure of pixel density. The more pixels you can squeeze into every inch of screen, the more closely packed together they are and the less visible each pixel is.
The second number is the typical viewing distance. To be a Retina display, individual pixels need to be invisible to the naked eye at typical viewing distance. For smartphone or tablet devices, that combination of numbers seems to be about 300PPI at 10 to 12 inches from your face.
As you’ve probably already realized, there’s a third number that has to be part of the retina equation: display size.
While you might hold a tablet or phone at arm’s length, a laptop or desktop monitor is generally further away than that. Partly because of the device form factor, but mainly because those displays are too large to view comfortably at 10 inches from your face. When we get to televisions, the pixel density could be much lower than 300PPI, but still count as “retina” because you typically view them from 6 feet or more away.
If you want to know whether a given display on a non-Apple device would qualify for the Retina branding, you can use an online calculator to get an accurate idea.
Retina Displays Require Software Changes
Even a Retina display can’t add detail into an image that isn’t there to begin with. If the image on screen has a lower resolution than the display itself, then the real physical pixels are essentially grouped together into larger virtual pixels to display the image. It’s effectively a form of digital zoom and can look pixelated depending on how large the disparity is.
While there’s not much you can do about low resolution images on websites and the like, the real problem comes from system elements such as text and icons. If they have to be upscaled, they end up looking very chunky. A Retina iPhone, for example, has four times the pixel density of its non-Retina forebears.
This means that iOS needs to display assets at four times the detail level to really take advantage of the high-resolution display. That takes additional computing power and memory. The good news is that Apple Silicon is incredibly power efficient and has plenty of horsepower, so it hasn’t been much of a problem.
App developers have to be mindful of Retina resolutions and how their apps look. Video games in particular can’t hope to render images at the native Retina resolution and remain playable. So developers have to use upscaling tricks to prevent the final image from looking blocky or blurry.
Is Retina The Way to Go?
Side-by-side, Retina displays are clearly superior to ones with lower pixel density. However, high pixel density devices have plenty of downsides. For one thing, they are much more expensive! Devices with such high resolutions can have shorter battery lives and there’s the aforementioned performance hit.
Apple has done a great job of balancing Retina resolutions with all of these other factors, but don’t think Apple’s the only one to achieve these resolutions. Many other flagship (and now mid-range) devices have pixel densities close to or above 300PPI. Sometimes without the equivalent of Apple’s careful balancing act.
For example, some Samsung Galaxy flagship phones offer users the option of running the actual image at a lower resolution than the screen is capable of. Only their latest models can display full-resolution images at high refresh rates while still achieving adequate battery life. Older phones have only been able to offer two of these options at the same time.
Retina display tablets in particular are fantastic for reading high-resolution graphic novels and comic books and, of course, for working with high-quality photos. On phones, their main advantage is simply being extremely pleasing to the eye. Images appear painted into the glass rather than a slightly fuzzy digital projection.
Eventually, retina-grade pixel densities will become the norm across all devices and all brands. But if you want a taste of that pixel-perfect future today a Retina display is a great choice.
