Explanation of digital camera terms

AE is the abbreviation of automatic exposure control device. AE lock is locked in a certain AE setting, which is used to manually control the exposure during automatic exposure to ensure the normal exposure of the subject.

There are several points to pay attention to when using AE lock:

1. AE lock cannot be used in manual mode and self-timer.

2. Do not adjust the aperture size after pressing AE lock.

3. When shooting with a flash, do not use (AE) lock.

Charge coupled device

Charge-coupled devices, like the negatives of traditional cameras, are circuit devices that sense light. You can think of it as tiny sensing particles scattered behind an optical lens. When light and images are projected onto the CCD surface through the lens, the CCD will generate current and convert the sensed content into digital data for storage. The more CCD pixels, the larger the size of a single pixel, and the clearer the collected image. Therefore, although the number of CCD is not the only key to determine the image quality, it can still be used as one of the important standards of camera grade.

Complementary metal oxide semiconductor

Complementary metal oxide semiconductor. Complementary metal oxide semiconductor. Early CMOS was a monolithic MC 1468 18A(DIP package), and 64 bytes were used to store system information. With the development of microcomputer and the increase of settable parameters, the capacity of CMOS RAM is generally 128 bytes, and the maximum is 256 bytes. Nowadays, CMOS manufacturing technology is also applied to the production of photosensitive elements of digital imaging equipment, especially monocular digital cameras with large film specifications. Although the use of CMOS circuits is very different from the firmware or computing tools in the past, CMOS technology is still basically adopted.

DPOF

DPOF refers to digital printing sequence instruction, which is used to record information on storage media (image memory card, etc.). ). In this format, you can set the number of images to be printed.

EXIF

EXIF (exchangeable image file format for digital cameras) is a specification formulated by jeita (Electronic Information Technology Industry Association) to determine the way to record additional information on jpeg images and sounds.

EXIF 2.2

EXIF version 2.2 is a newly revised digital camera file format, which contains all kinds of shooting information needed to achieve the best printing.

PTP

PTP is the abbreviation of English picture transmission protocol. PTP is the standard first negotiated by Kodak and Microsoft. Image devices that meet this standard can be better shared by systems and applications after accessing Windows XP system, especially in network transmission. The system can directly access these devices, upload pictures when creating online photo albums, and transmit pictures when chatting online. Of course, this is mainly for the convenience of ordinary users with little computer knowledge, and it is easier to combine cameras, application software and websites to complete some stupid functions.

GT lens

GT lens refers to the unique design of Minolta's multi-piece and multi-group lens combination. The lens is made of high-grade low-dispersion optical glass, including several die-casting aspheric lenses and so on. In other words, Minolta's G-series high-end professional traditional camera (silver salt camera) uses AF lens. Minolta applies the technology of producing G-series lens to the design and production of digital cameras, and the product produced is called GT lens.

Zeiss lens

Zeiss. Zeiss is a German enterprise, which is committed to applied research, development, manufacture and sales of high-quality products such as optics, glass technology, precision technology and electronic products. Starting from 1846, Carl Zeiss set up a workshop to produce microscopes. Zeiss lens, professional camera, photographic lens

wide-angle lens

That is, wide angle, also known as short lens. Because the focal length of the wide-angle lens is very short, the scene projected on the basement membrane becomes smaller and the shooting angle of the lens becomes wider. Wide-angle images can not only shoot more scenes, but also shoot in narrow environments.

Pixel number

The number of pixels in a digital camera includes effective pixels and maximum pixels. Different from the largest pixel, the effective pixel refers to the pixel value that really participates in photosensitive imaging, while the value of the highest pixel is the real pixel of photosensitive device. This data usually includes the non-imaging part of the photosensitive device, and the effective pixel is the value converted under the zoom ratio of the lens. For the digital camera pixels of mobile phones, it can only be in the primary development stage, and the number of pixels is not very high, mostly between 65438+ 10,000-1.3 million pixels. The larger the number of pixels in a digital camera, the greater the resolution of a still image, and the space occupied by a corresponding picture will also increase.

resolution ratio

Resolution and pixel are two very similar concepts, but they are different. Relatively speaking, resolution refers to the number of pixels above the unit imaging size. Generally speaking, the larger the pixel, the higher the resolution. For a picture, the pixels are fixed, but the resolution can be changed at any time. With the enlargement of the image, the resolution will gradually decrease.

intelligent electro selective pattern

IESP intelligent electronic selection mode. IESP autofocus means that a digital camera is divided into several blocks within the focus range (some data say that the division method is sector division), and then the focus position measured by the divided blocks is comprehensively calculated, and the best focus position is determined according to the different states of the subject. IESP autofocus often appears in the introduction of Olympus digital cameras.

hum

Another focus of the lens is zoom capability, including optical zoom and digital zoom. Although both of them are helpful to enlarge distant objects in telephoto shooting, only optical zoom can support adding more pixels after the main body of the image is imaged, making the main body not only larger, but also relatively clearer. Usually, the larger the zoom factor, the more suitable for telephoto shooting. Optical zoom, like traditional camera design, depends on the focal length of the lens, so the resolution and image quality will not change. Digital zoom can only reduce the size of the original image and make the image larger on the LCD screen, but it does not help to clarify the details.

optical zoom

Optical zoom relies on optical lens structure to achieve zoom. The zoom mode is similar to that of a 35mm camera, that is, the scene to be shot is enlarged and reduced by the movement of the camera lens. The larger the optical zoom factor, the farther the scene can be shot. At present, the optical zoom magnification of digital cameras is mostly between 2 and 5 times, and the optical zoom effect of some code cameras reaches 10 times. The optical zoom factor of home camcorder is 10 ~22 times, and it can clearly shoot things 70 meters away. Using a magnifying glass can increase the optical zoom factor of the camera.

digital zoom

That is, digital zoom is actually an electronic amplification of the picture. Some pixels on the original CCD image sensor are enlarged by interpolation, and the pixels on the CCD image sensor are enlarged to the whole picture by interpolation algorithm. Through digital zoom, the shot scene will be enlarged, but its definition will be reduced to some extent, which is a bit like the zoom function in VCD or DVD, so the practical significance of digital zoom is not great.

Intelligent zoom

New and unique Sony smart zoom function. It can enlarge and reduce, without enlarging particles, so that the enlarged image can maintain the original detail quality. Intelligent zoom provides different degrees of enhanced zoom function according to the choice of different image sizes. Unlike digital zoom, intelligent zoom can maintain the same image quality as the original image.

Program automatic exposure

Programmable automatic exposure is the product of the combination of electronic technology and artificial intelligence. When exposed in this way, the camera can not only calculate the appropriate exposure according to the light conditions, but also automatically select the appropriate exposure combination.

hyperfocal distance

Because the back depth of field of the lens is relatively large, people call the distance that can be clearly imaged after focusing as hyperfocal distance. The scenery in hyperfocal distance is not really clearly imaged. Because there is no focus, it must be blurred, but the degree of blur is generally acceptable. This is the reason why the negative film taken by a fool's camera can't be enlarged too much.

LCD frame

The LCD viewfinder is a liquid crystal display. There are black and white and color, and color has true color and false color. Pseudo color is cheap, but the effect is poor. The LCD used for framing and playback in digital cameras is almost the best TFT true color at present. There are two types of TFT LCD: reflective and transmissive. Reflective light reflects ambient light to the front, which is very different from different angles, and the display is dark, but it saves electricity and has low cost. The transmission type works by the light behind it, with small angle change and bright display, but it consumes a lot of power.

Organic Light Emitting Diode (abbreviation for organic light emitting diode)

Organic Light Emitting Diode, organic light emitting diode in English, organic light emitting diode display technology has the characteristics of self-luminescence, using very thin organic material coating and glass substrate, when current passes through, these organic materials will emit light, and the organic light emitting diode display screen has a large viewing angle, which can significantly save electricity.

TTL SLR frame

This is a necessary way to find scenery on a professional camera, and it is also a truly error-free optical way to find scenery. The viewfinder can reach 95% of the real shot. The only drawback is that if the lens is too small, the viewfinder will be very dark, which will affect the manual focusing. Fortunately, everyone has autofocus, and this shortcoming is no longer a big problem. Of course, in order not to be too dark, manufacturers will use large-caliber advanced lenses, so semi-professional cameras are generally equipped with such lenses. Olympus cameras often use this viewfinder.

electronic viewfinder

Electronic viewfinder (EVF), the field of view ratio of electronic viewfinder is much larger than that of optical viewfinder. For example, the EVF of Sony DSC-f707 has a field of view ratio of 99%. Electronic viewfinder is also more practical, not only cheaper, but also more energy-saving when used, and can be used in any ambient light. Although the viewing angle and color effect in the viewfinder are not exactly the same as the final effect, they will adapt quickly after being used for a period of time.

optical viewfinder

The components commonly used in traditional mass cameras to view through a set of lenses that have nothing to do with the shooting lens (often linked with the zoom lens on high-end stupid machines) have low cost, but they have parallax, and what they see is not entirely taken by themselves.

Universal optical frame

This is the most common framing method, and the only disadvantage is the large framing error. Friends who have used digital cameras must know that when the optical viewfinder of digital cameras is shooting at close range, there are great errors between the up, down, left and right positions and the actual shooting scene (it is not particularly obvious when it is far away). Generally speaking, the scene seen by the optical viewfinder accounts for about 85% of the actual shooting scene.

Multiple measurement mode

It is equipped with three metering modes: fixed-point metering, central offset metering and multiple metering modes to meet different shooting conditions and uses. Multi-metering mode divides the image into 49 areas, and metering each area, so that the photographed image can get a balanced exposure.

Closed exposure

Surrounding is an advanced function of the camera. Closed exposure means that when you press the shutter, the camera does not shoot at once, but shoots multiple photos in succession with different exposure combinations, thus ensuring that one photo always meets the photographer's exposure intention. To use bracketing exposure, you need to set it to bracketing exposure mode first, and shoot as usual when shooting. Closed exposure is generally used for static or slow-moving subjects, because it is difficult to capture the best shooting opportunity of moving objects because of continuous shooting of multiple shots.

Pre-flash exposure

Special pre-flash exposure function can measure the flash intensity and exposure value more accurately by using the image data received during pre-flash during general shooting or macro shooting, so that the shot image can get better exposure.

Red-eye prevention function

It refers to the phenomenon that the photographer's eyes appear red spots because of the reflection of the blood vessels in the fundus of the subject when shooting a portrait with a flash. But most mainstream digital cameras have red-eye prevention function, but if they are not turned on, they still won't work.

Handshake function

There are two functions of digital camera to prevent hand shock: one is optical and the other is digital. Optical hand shock prevention is the same as traditional camera. The lens designed by the special envoy is arranged in the imaging optical path, which can sense the vibration of the camera and automatically adjust the optical path according to the characteristics and degree of vibration to make the imaging stable.

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Interpolation, sometimes called "reset sample", is a method to increase the pixel size of an image without generating pixels. According to the color of surrounding pixels, the color of missing pixels is calculated by mathematical formula. Some cameras use interpolation to artificially increase the resolution of images.

TTL photometry

That is TTL photometry. Measuring the luminous flux through the lens has nothing to do with the parameters such as filter exposure and aperture focal length. Measurement methods are divided into average measurement, local measurement and centralized measurement. Any method of photometry is similar, but the contrast between light and shade of the subject is very different, such as backlight, or there will be different differences, such as photomicrography.

ISO photosensitive value

ISO sensitivity is a measure of the sensitivity of traditional camera negatives to light, which is usually expressed by ISO number. The larger the number, the stronger the optical rotation. Commonly used methods are ISO 100, 400, 1000, etc. Generally speaking, the higher the sensitivity, the coarser the particles of the negative film, and the worse the magnification effect. Digital cameras also use this ISO value to indicate the exposure used by the metering system.