The most used camera nowadays is not quite the shock camera in the mobile phone. Camera technology has evolved a lot in the recent decades. Back in the days, it seemed more or less unthinkable that a phone could ever contain an entire camera body. Thinks about how the camera has gone from an enormous chunk, until today when the camera is a natural part of every person’s everyday life.
The old traditional camera house differs in many ways from the new digital technology, but at the same time, the basis for how a camera works is quite similar. The word camera comes from the Latin word “camera obscura”, which means “darkroom”. A camera consists of 3 parts: 1) Lens, 2) Camera body and 3) Film/memory card.
In the camera body, there is a film, and the function of the lens is to project the object in front of the camera on the film in the camera body. The light from the object, which either “shines” by itself or reflects the light from some kind of flash, is called the incident light. The incident light enters through the lens and mirrors of the lens, where the light is refracted to hit the film in exactly the right place. If the camera is digital, the image is stored on a type of photosensitive panel which then digitally saves the information on a memory card.
To fully understand how a camera works, you need to familiarize yourself with some concepts. Below are some concepts and their brief description, some you may have heard before but may not really remember what it means.
What is Focal Length?
The focal length determines how much of the environment is actually included in the image, the “film”. But the term is more technical than that and is the distance between the optical center of the lens and its focal point (focus). For Focal Point, see below.
What is the focus (focus)?
The point inside the camera body, where the incident light radiates after it has been reflected and refracted through the lens. Sometimes called also a focal point.
What is the Aperture?
Inside the camera body, the film / photosensitive panel is in total darkness. To control how the light enters the camera body, it is protected and controlled by the Aperture and Shutter (see Shutter below). The aperture that sits in front of the shutter controls how much light comes in each time the shutter is opened and closed, ie the “diameter of the aperture”.
What is the Shutter?
The shutter opens and closes, and together with the aperture, the shutter controls how much light enters and hits the film / photosensitive panel. Since the Aperture (see above) controls how large the aperture becomes that lets in light, you control the Shutter with how long the aperture should be open to let in the light (shutter speed).