Listening Part 8: Summarize Spoken Text
PTE Listening Part 8- Sample 9: Summarize The Spoken Text
A long thin sheet made of flexible plastic and coated with chemicals sensitive to light and based on silver compounds known as a film was the most important part of an old-style camera. In order to take a picture on the camera, the photographer used to click a button and by this the small shutter in the front of the camera used to open briefly which allowed light to enter the lens. When light reacted with the film in the camera, the picture clicked used to be stored on it. However, this was just one phase, as after clicking the photographs, the camera had to be taken to an automated developer to get the final pictures. The procedure was that the developer opened the film container, dipped the film into a chemical, which made the photos appear in the forms of negatives as they used to be in the opposite direction of the actual photos clicked and finally a machine was used to turn the negative into pictures. However, with the passage of time, new developments took place and digital cameras came into use. Although this procedure is the same from the opening of shutter to light capturing on the lens, everything changes after that as there is no film, but a light detector instead of it. This detector was of two kinds: the charge-coupled device or a CMOS image sensor. When the light hits the sensor chip, it breaks into millions of pixels and stores each pixel as a number according to the color and brightness. This series of numbers is what is known as a photograph.