Photography through the years过去两百年来摄影技术的发展

　　Now, pretty much everyone has a camera in their back pocket – in the form of a smartphone. It's easy to take hundreds of photos without needing to really consider set up or storage. And it's very hard to imagine that, at one time, capturing an image was an almost impossible process.

　　Going back even before traditional film cameras, there were camera obscuras. These were boxes with a small hole in them. Through one side, an image could be projected onto a wall on the opposite side of the box. However, the picture was upside down, very faint, and couldn't be captured in physical form – a bit like the images we see on modern projectors. In 1839, a French artist managed to work out a way to store and save photographs. He projected the image onto a shiny metal plate treated with chemicals. These images were in black and white. The first colour photo ever taken was of a tartan ribbon. The image was composed of three black and white photographs, each taken through a red, blue or green filter.

　　So, how did we get from these early photographs to the kind we put into a frame and keep? Before the digital revolution, an image was captured on a negative, and this method is still chosen by some photographers today. A negative is an inverted image on a small strip of glass or plastic film which can then be exposed to light and processed onto photographic paper. When this was the main source of obtaining physical copies of photographs, it was a lengthy process with customers having to take the negatives to a shop and wait for their pictures to be developed.

　　That was until digital photography came along in the 70s. Digital cameras captured images that could be saved as files and manipulated on a computer. Those are the kind of photos we take today on our phones.

　　So, don't take the camera in your pocket for granted. It's been years in the making.

　　词汇表

　　smartphone 智能手机

　　set up 设置

　　storage 储存

　　capture 拍摄，捕捉

　　film cameras 胶片相机

　　camera obscura 暗箱

　　project 投映

　　upside down 上下颠倒的

　　faint 虚的，不清晰的

　　projector 投影仪

　　treat （用特殊物质）处理

　　colour photo 彩照

　　filter 滤镜

　　frame 相框

　　digital 数字的

　　negative 底片

　　inverted 颠倒的

　　film 胶卷

　　expose to 暴露于…

　　process 冲洗加工（底片）

　　photographic paper 相纸

　　develop 冲洗（底片）

　　manipulate 处理，修饰