Camera lens
From Simple English Wikipedia, the free encyclopedia
A camera lens is usually made of glass and is part of a camera. A lens is needed if you want to take a picture. The lens makes an image by focusing the light on the film. (In a digital camera the film is replaced with a computer chip.)
Many cheap cameras only have one lens that you cannot change or take out. This is called a fixed lens design. More expensive cameras usually have lenses that come off, so you can take out one lens and put in another. Depending on what you wish to photograph, you can use different lenses (objectives) to make a different kind of picture. For instance, to take a picture of something far away you might use a zoom lens. There are many kinds of lenses.
The study of lenses and how they work is called optics.
For camera lens, it is most difficult to understand the lens design for large format. There is over hundred year effort to provide various ways to get good pictures. These lenses, some used even before World War II, are still usable today. Computers now let engineers make better lenses, though, because they can calculate the way that light goes through the lens and find the best design for each task.