1. The lens
2. The aperature
3. The shutter
4. The film
The lens is the “eye” of the camera – in some respects its most vital part. Understanding a few basic facts about lenses can help you use your lens more effectively to get the results you want. Let’s concentrate on two important practical characteristics of any lens – its speed and its focal length. To take truly great pictures it is necessary to have a working knowledge of what an “F stop” is and what effect it has on a picture, and how focal length can be used in controlling image size and perspective.
The aperature is the opening that allows light through the lens and to the film, and the shutter covers the film until we are ready to expose it to light. Changing the aperature and the speed of the shutter changes the amount of light collected by the film and thus the level of exposure.
The film captures the image by collecting light on its surface which causes chemical reactions on the film.
