1. That’s not a ghost in your picture, It’s just the way your digital camera works. (SQA_6)
在你的照片里那不是鬼，只是你的数码相机的工作原理所致。
There has been a clear relationship between technological development over the years and a fascination with ‘ghost’ photography. 多年来技术的发展与对“鬼魂”摄影的迷恋之间存在着明显的关系。SImages of unexplained circles of light, ghostly mists and human-shaped images fill social media pages on the internet. 不明原因的光环、幽灵般的薄雾和人形图像充斥着互联网上的社交媒体页面。SThe explanation is simple: few people realise how digital cameras work. 原因很简单：很少有人了解数码相机的工作原理。SThe fact that an image only ‘appeared’ in the photo, but not real life, is not a sign of its ghostly origins. 照片中仅“出现”的图像在现实生活中不存在，这并不是其幽灵起源的标志。SIn fact, it is a perfectly normal part of digital photography. 事实上，这是数码摄影中完全正常的一部分。SScientists call them ‘photographic artefacts’, because they show things that only exist because it is a photograph. 科学家称它们为“摄影伪影”，因为它们展示的东西只因为这是一张照片才存在。SPut simply, contrary to popular belief, things in photos look different from real life. 简单地说，与普遍看法相反，照片中的事物看起来与现实生活不同。S
The biggest cause of photographic artefacts is the contrast between how the ‘depth of field’ works in modern cameras and in the human eye. 摄影伪影产生的最大原因是现代相机和人眼的“景深”工作方式之间的对比。SThis is because, although it is now possible to take excellent pictures of things far away, the quality of photos of objects that are very near is less accurate. 这是因为，虽然现在可以拍摄远处物体的出色照片，但非常近的物体的照片质量却不太准确。SLight causes these misrepresentations. 光线导致了这些失真。SThe level of light never changes when humans stare at objects. 当人类盯着物体看时，光线强度永远不会改变。SHowever, this is not what happens with digital cameras. 然而，数码相机并非如此。SWhen a camera points at a light, the light becomes stronger and stronger. 当相机对准光源时，光线会变得越来越强。SOrbs, which are perfect circles of light, are the most common photographic artefact and they are often the result of light reflecting off water or insects in the air near the camera. 光环，即完美的圆形光源，是最常见的摄影伪影，它们通常是光线从相机附近空气中的水或昆虫反射的结果。S
It is easy to see why humans see differently from digital cameras. 很容易理解为什么人类与数码相机的看法不同。SHowever, digital cameras are also significantly different from the old film cameras. 然而，数码相机也与老式胶片相机有很大的不同。SIn many ways, digital cameras give less reliable results. 在很多方面，数码相机的结果不太可靠。SFor example, modern functions allow digital cameras to scan the image more than once over a period of less than a second, or to automatically select how long the lens is open. 例如，现代功能允许数码相机在不到一秒的时间内多次扫描图像，或者自动选择镜头打开的时间。SGenerally, this produces better photos, but if the camera moves during the photo, it may record multiple images, creating the appearance of ghostly forms. 通常，这会产生更好的照片，但如果在拍照时相机移动，它可能会记录多个图像，造成幽灵形态的出现。SGhostly mists often appear when the camera picks up the photographer’s own breath on a cold night when the lens is open for longer. 在寒冷的夜晚，当镜头长时间打开时，相机捕捉到摄影师自己的呼吸，就经常会出现幽灵般的薄雾。SThis never happened with film cameras. 胶片相机从未发生过这种情况。S
Filming under certain conditions will often produce unusual light effects in digital prints. 在某些条件下拍摄往往会在数码照片中产生不寻常的光效。SFor instance, glass often makes objects such as a light source behind the photographer appear in the printed photo. 例如，玻璃经常会使摄影师身后的光源等物体出现在打印的照片中。SIf the glass is clean, it may not be obvious that there was a window and all you see is an object that ‘wasn’t there when I took the photo’. 如果玻璃干净，可能不明显有窗户，而你看到的只是一个“我拍照时不在那里的物体”。SA famous UFO photograph showed two clear bright saucer-shaped objects flying across a blue sky. 一张著名的不明飞行物照片显示两个清晰明亮的碟形物体在蓝天上飞过。SAlthough very believable, it was, in fact, just a reflection of some streetlights behind the photographer. 尽管非常可信，但实际上，它只是摄影师身后一些路灯的反射。S
Most digital cameras come with a good zoom function, letting us take photos from far away. 大多数数码相机都有很好的变焦功能，让我们可以从远处拍照。SHowever, at some point, digital cameras can no longer produce clear images anymore. 然而，在某些时候，数码相机不再能产生清晰的图像。SAs you go nearer, instead of seeing the image as a continuous picture, the digital image becomes pixelated, which means it appears as a group of coloured rectangles. 当你靠近时，数字图像不再是连续的画面，而是变成像素化，这意味着它呈现为一组彩色矩形。SWhat you see in print is very different from the object in real life, and the purest example of an artefact of the pixellation process. 你在照片中看到的与现实生活中的物体非常不同，这是像素化过程产生的伪影的最纯粹的例子。SAs humans, we specialise in recognising faces or familiar things in random patterns, and may start to imagine things that were not there. 作为人类，我们擅长在随机图案中识别面孔或熟悉的事物，并可能开始想象不存在的东西。SIn one case, an image with the physical appearance of a ghostly face in a red top appeared in a photo. 在一个案例中，一张照片中出现了一个穿着红色上衣的幽灵般的脸的图像。SZoom out, and it looks more like a doll. 缩小图像，它看起来更像一个洋娃娃。SZoom out further, where the camera can cope with the amount of information it receives, and you can see it’s actually a rope holding up a flag. 再进一步缩小，在相机能够处理它接收到的信息量的地方，你会发现它实际上是一根挂着旗子的绳子。S
A final group of photos have started appearing on the internet. 最后一组照片开始出现在互联网上。SFakes, images created by computer, are not as common on internet sites as you’d imagine, even though it’s possible to produce believable images with photo-editing software. 假照片，即由计算机创建的图像，在互联网网站上并不像你想象的那么常见，尽管使用照片编辑软件可以制作出可信的图像。SMany smartphones contain apps which make it very easy to produce versions of photos with human forms added. 许多智能手机都包含应用程序，可以非常容易地制作添加了人形的照片版本。SMost of these are easy to spot. 其中大多数都很容易被发现。S
In considering photographic artefacts, it is necessary to also consider the story. 在考虑摄影伪影时，也有必要考虑这个故事。SIn many cases, the ghostly nature depends entirely on the fact that the photographer’s claim ‘that wasn’t there when I took the photo’. 在许多情况下，是否是幽灵的本质完全取决于摄影师声称的“我拍照时那里没有这个”。SOften the unexpected appearance of an orb or mist in a photo leads the owner to make enquiries, 照片中光环或薄雾的意外出现往往会导致所有者进行询问，Sand once they start to share information with people who believe the place or area to be haunted, they become aware of the possibility that the story could be true. 一旦他们开始与认为这个地方闹鬼的人分享信息，他们就会意识到这个故事可能是真的。SSuch photos end up relying on witness statements to support the claims, which are often unreliable. 这些照片最终依赖证人的陈述来支持这些说法，而这些陈述往往不可靠。SOne thing is sure: ghostly images will continue to appear until smart phone technology moves on. 有一件事是肯定的：在智能手机技术进步之前，幽灵般的图像将继续出现。 S