The meaning and function of each parameter of a digital camera

The meaning of each parameter and its function are as follows:

Effective Pixel Number

Effective pixel number refers to the value of the pixels that are actually involved in light-sensitive imaging. The highest pixel value is the real pixel of the sensor, and this data usually includes the non-imaging part of the sensor, while the effective pixel is the value converted at the lens zoom magnification.

Optical zoom

Digital cameras rely on an optical lens structure to achieve zoom. The optical zoom of a digital camera is similar to that of a traditional 35mm camera, in that the lens moves to zoom in and out of the scene to be photographed, and the larger the optical zoom magnification, the farther away the scene can be photographed.

Photosensitive device

Compared with traditional cameras, traditional cameras use "film" as its carrier of recorded information, while the digital camera "film" is the imaging sensor, and is integrated with the camera, is the heart of the digital camera. It is the heart of the digital camera. The sensor is the core of a digital camera and the most critical technology.

The development path of digital camera can be said to be the development path of the sensor. At present, there are two kinds of core imaging components in digital cameras: one is the widely used CCD (charge-coupled) element; the other is the CMOS (complementary metal-oxide conductor) device.

Digital zoom

Digital zoom is the processor within a digital camera that increases the area of each pixel within a picture to achieve magnification. This technique is similar to using image processing software to change the area of the picture to a larger size, but the program is carried out in the digital camera, the original CCD image sensor on a portion of the pixels using "interpolation" processing means to do enlargement, the CCD image sensor on the pixels using interpolation algorithms will be enlarged to the whole picture.

Display One of the biggest differences between a digital camera and a traditional camera is that it has a screen on which pictures can be viewed in a timely manner, which is called the display of the digital camera, and it is generally a liquid crystal structure (LCD, full name Liquid Crystal Display).

Type of LensThe lens of a digital camera consists of multiple lenses, and the material is categorized into two types: glass and plastic. If a digital camera lens is made of glass, many users and businesses say that glass lenses provide better light transmission and project a clearer image.

But many current test reports show that glass lenses don't necessarily provide a clearer image than plastic, and glass lenses may also increase the weight of the camera, so you should do more than just look around when you're buying, and don't get stuck on the lens material.

Aperture

The aperture is a device used to control the amount of light that passes through the lens and enters the light-sensitive surface of the camera body, which is usually inside the lens. The aperture values we usually refer to as F2.8, F8, F16, etc. are aperture "coefficients", relative to the aperture, not the physical aperture of the aperture, which is related to the physical aperture of the aperture and the distance from the lens to the light-sensitive device (film or CCD or CMOS).

The smaller the aperture F value, the more light is fed into the camera in the same unit of time, and the amount of light fed into the upper level is just double the amount of light fed into the lower level.

For consumer digital cameras, the aperture F value often ranges from F2.8 to F16. In addition, many digital cameras can make 1/3-level adjustments when adjusting the aperture.

Shutter

A shutter is a device on a camera that controls the effective exposure time of the sensor.

The working principle of the shutter is this, in order to protect the camera's light-sensitive devices, not to exposure, the shutter is always closed; shooting, adjust the shutter speed, as long as the camera's shutter release knob (that is, the button to take a picture), in the shutter open and closed between the gaps, so that through the photographic lens of the light, so that the camera within the photographic plate to obtain the correct exposure, the light through the shutter The light passes through the shutter and enters the light-sensitive device and is written to the memory card.

As for the common B shutter function of DSLRs, although you can freely decide the length of exposure time, shooting flexibility is higher, but most current consumer digital cameras are not yet able to support, at most, to provide such as 2 seconds, 8 seconds, 16 seconds, and other slower speeds of the default value.

Flash

Flash is also one way to enhance exposure, especially in dimly lit areas, and hitting the flash helps brighten up the scene. There are also drawbacks to using the flash,

The continuous shooting function

is designed to capture photographic moments by saving time on data transfer. Continuous shooting mode allows you to take multiple photos in a row in a short period of time by loading data into the digital camera's internal high-speed memory (cache) instead of transferring data to a memory card.

Because a digital camera shoots through the processes of photoelectric conversion, a/d conversion, and media recording, both conversion and recording take time, and recording in particular takes more time. As a result, all digital cameras are not very fast at continuous shooting.

Movie recording

This means that digital cameras have the ability to record video files. Unlike DV (Digital Video Camera), digital cameras can only store video files in the memory card, and since the memory space is limited, the quality and size of the video files are poor.　　

Recording function

The function of recording through the microphone that comes with the digital camera. Since it is not a professional camcorder or recorder, the audio recorded by a digital camera is mono. The recording functions of digital cameras can be broadly categorized into three types: live clip recording, labeled voice files and pure recording.

Storage media

Digital cameras convert image signals into data files that are stored on magnetic devices or optical recording media. If a digital camera is the mainframe of a computer, then the memory card is equivalent to the hard disk of the computer. The storage memory can record other types of files in addition to image files, and it becomes a removable disk when connected to a computer via USB.

The common storage media on the market are CF card, SD card, MMC card, SM card, Memory Stick (Memory Stick), xD card and small hard disk MICRoDRIVE).

Scene Mode

Generally, aperture, shutter, focal length, metering, and flash are pre-adjusted in the digital camera to allow less experienced users to take quality digital photos.

To make it easier for beginners, digital camera manufacturers have added several scene modes to digital cameras, making it easier to take quality pictures. Currently, there are as few as four or five scene modes in a digital camera, and as many as 20 or 30.

Batteries

Digital cameras require batteries to function properly. Generally, digital cameras can use dry cell batteries, alkaline zinc-manganese batteries, cadmium-nickel batteries, hydrogen-nickel batteries, lithium-ion batteries, and lithium batteries as their power source.

Expanded Information

A Brief History of Digital Camera Development

The history of digital cameras can be traced back to the 1940s and 1950s, with the invention of the videotape recorder (VTR) by Bing Crosby Laboratories in 1951, a new machine that could record electrical impulses from a television broadcast onto magnetic tape. By 1956, VCRs were in mass production. It is seen as electronic imaging technology produced.

In the 1960s NASA had to survey the surface of the moon before astronauts could be sent there. However, engineers found that the analog signals transmitted back from the probe were so weak, caught among other rays in the universe, that receivers on the ground couldn't turn the signals into clear images. So the engineers had to find another way.

Digital imaging technology has evolved much more rapidly since then, thanks in large part to technological competition during the Cold War. And these technologies were also used primarily in the military, with most spy satellites using digital imaging technology.

Research and development of the "CCD chip" began as early as the 1960s, and in 1969 George Smith and Willard Boyle of Bell Labs combined videophones and semiconductor bubble storage technology to design a "charge" that could be conducted along the surface of a semiconductor by a digital camera. George Smith and Willard Boyle of Bell Labs combined videophones and semiconductor bubble storage technology to design a "Charge 'Bubble' Device" that could conduct charge along the surface of a semiconductor for a digital camera, pioneering the invention of a prototype CCD device.

The purpose of the CCD invention at the time was to improve storage technology, and the component itself was used as a mere memory. It was then recognized that CCDs could use the photoelectric effect to capture and store images.

References:

Baidu Encyclopedia Digital Camera