What Is a Camera?
A camera is an electrical device that uses a lens and photosensitive materials to take and store pictures. Cameras built into products such as smartphones are sometimes called camera modules.
Camera Mechanism
A camera is mainly composed of three elements: lens, photosensitive material, and shutter.
1. Lens
A lens is a component made of glass or plastic that refracts light. Focus is adjusted by moving part or the entire lens back and forth. Today, most cameras are equipped with an autofocus function that automatically focuses the camera. Compact digital cameras use the contrast detection method, which adjusts the lens to a high-contrast position.
On the other hand, SLR digital cameras use the phase detection method, in which incoming light is divided into two parts and the images formed are compared to adjust the focus.
The latest technology is image recognition autofocus, which detects and focuses on a person’s face.
2. Photosensitive Materials
In a film camera, the chemical coating on the surface of the film changes when it is exposed to light (photosensitized), and the film is developed through a chemical process. In contrast, the digital cameras commonly used today use an imaging element (image sensor) instead of film. The light received by the photodiode is converted into electric current and voltage, and stored as digital data in each unit called a pixel. There are several types of image sensors, such as CMOS sensors and CCD sensors, classified according to their circuit structure.
3. Shutter
The shutter is a component that regulates the time and timing of light exposure to photosensitive materials. The lens shutter used in compact cameras is placed inside the lens and is quickly opened and closed by a spring. SLR cameras use a focal plane shutter that is placed just in front of the photosensitive material. The shutter speed indicates the time the shutter is open (exposed).
Types of Cameras
Cameras can be divided into two main categories: digital and film.
There are also other types of cameras as follows:
1. Single-lens Reflex Camera
SLR cameras are cameras that allow the photographer to view the image directly through a viewfinder by reflecting it in a mirror, etc. The ability to shoot and view with a single lens is what gives them the name SLR, from the word reflex (reflection). SLR cameras have been used as the upper end of the mainstream. Lenses of this SLR cameras are interchangeable.
2. Mirrorless SLR
This is a digital camera with a small LCD inside the viewfinder that displays real-time digital data. Compared to SLR cameras, mirrorless cameras have the advantage of being compact. The time lag and price have been improved, and they are now replacing SLR cameras in the mainstream. Lenses of mirrorless SLR cameras are interchangeable.
3. Compact Camera
Compact cameras are small cameras in which the lens and camera are integrated into a single unit.
4. Instant Camera
Instant cameras are film cameras that can be developed immediately after shooting.