how to take a picture with a film camera
Film is very sensitive to light: only a tiny amount of light energy is needed to make a photograph and too much light will destroy it. To produce a perfect photo, you have to let exactly the right amount of light hit the film, which is called the exposure. The exposure depends on two factors: how long the shutter is open (the shutter speed) and how widely it's open (the aperture). Shutter speed is measured in seconds (anything from about 1/10,000 second to 30 seconds); aperture is measured in units called f-stops (or just "stops" for short), such as f/4 and f/8, with higher f numbers meaning more light is let in.
Automatic, compact, "point-and-shoot" cameras produce a reasonable image with the click of a single button: they use photocells (electronic light sensors) to automatically adjust the shutter speed and aperture and fire out invisible infrared or ultrasound beams to set the focus automatically as well. Although sophisticated professional cameras often have automatic controls, they also allow completely manual operation: before you can take a photo, you have to adjust the focus, set the exposure time, and adjust the size of the aperture. With manual cameras, you have to adjust the exposure time and aperture setting to compensate for one another, because both of them affect the amount of light reaching the film.
Automatic, compact, "point-and-shoot" cameras produce a reasonable image with the click of a single button: they use photocells (electronic light sensors) to automatically adjust the shutter speed and aperture and fire out invisible infrared or ultrasound beams to set the focus automatically as well. Although sophisticated professional cameras often have automatic controls, they also allow completely manual operation: before you can take a photo, you have to adjust the focus, set the exposure time, and adjust the size of the aperture. With manual cameras, you have to adjust the exposure time and aperture setting to compensate for one another, because both of them affect the amount of light reaching the film.