Common sense of photographic terminology

1. What are the common terms in photography?

Focal length: the distance from the center of the lens to the clear image formed on the film plane (other photosensitive materials).

The focal length is usually in millimeters (mm) and is usually marked in front of the lens. For example, we usually use 27-300 mm, 50mm (also known as "calibration lens", referring to 35mm film), 70mm and so on. (telephoto lens). Aperture: A device that controls the amount of light passing through a lens.

If you open the first aperture, the amount of light entering the camera will double, and if you narrow the first aperture, the amount of light will be reduced by half. The aperture size is expressed by the value of f, and the order is as follows: f/ 1, f/ 1.

The fourth floor, the second floor, the second floor, the eighth floor, the fourth floor and the fifth floor.

6, f/8, f/ 1 1, f/ 16, f/22, f/32, f/44, f/64 (the smaller the f value, the larger the aperture). Shutter: Device for controlling exposure time.

Generally, it can be divided into mirror shutter and focal plane shutter. Shutter speed: the time when the shutter is open.

It refers to the time (exposure time) when light sweeps across the film (CCD). For example, "1/30" means that the exposure time is 1/30 seconds.

The shutter speed of1/60s is twice that of1/30s. The rest and so on.

Depth of field: the relatively clear range of an image. Depth of field depends on three factors: focal length, camera distance and aperture size.

The relationship between them is: (1 The longer the deer distance, the shorter the depth of field; The shorter the focal length, the longer the depth of field; (2) The longer the shooting distance, the longer the depth of field; (3) The larger the aperture, the smaller the depth of field. Further reading: What is the preview of depth of field? In order to see the actual depth of field, some cameras provide a preview button of depth of field. Press the button to reduce the optical ring to the selected size, and the scene you see after shooting is the same as that recorded on the film (memory card).

Sensitivity (ISO): Indicates the photosensitive speed of photosensitive materials. Units are expressed in degrees or fixed. For example, "IS0 100/2 1" means that the fixed sensitivity of the film is 100 degrees /2 1.

The higher the sensitivity, the more sensitive the film is (that is, the less light is needed to shoot the same photo normally in the same shooting environment, that is, a higher shutter or a smaller aperture can be used). Color temperature: Different pigments contained in different light are called "color temperature".

The unit is "k". The color temperature we usually use is 5400 K-5600 K; The color temperatures that light types A and B can adapt to are 3400K and 3200K respectively.

Therefore, different types of films should be selected according to the subject and environment, otherwise there will be color cast (unless the color temperature is corrected by color filter). White balance: Due to the different spectral characteristics under different lighting conditions, the photos taken often have color deviation, such as blue under fluorescent lamp and yellow under incandescent lamp.

In order to eliminate or reduce this color shift, digital cameras can adjust color settings according to different lighting conditions, so that the color of photos is as undistorted as possible. Because this adjustment is often based on white, it is called white balance.

Exposure: The process in which light reaches the surface of the film and makes the film sensitive. It should be noted that by exposure, we mean film exposure, which is a necessary process for us to obtain photos.

Often depends on the combination of aperture and shutter, so there is the word exposure combination. For example, when the shutter measured by the exposure meter is 1/30 seconds, the aperture should be 5.

6, like this, F5. 6, 1/30 seconds is an exposure combination.

Exposure compensation: used to adjust underexposure or overexposure. "Stop": This is a unit to measure brightness, but only if there is a reference object.

You can't say that an object is three stations brighter, but you can say that object A is three stations brighter than object B, but this is not entirely in line with its original intention.

It is the unit of brightness change. But only if there is a reference.

This method is used because there is no standard boundary to define light and shade. A black stone will look brighter in a bright place than a gray stone in the dark.

Blur: The picture is not clear. It may be caused by camera defocus and jitter.

Pixel: Simply speaking, it is the number of photoelectric sensors on CCD/CM0S. The photosensitive element forms a point on the output photo after the steps of photosensitive, photoelectric signal conversion and A/D conversion. If you enlarge the image several times, you will find that these continuous tones are actually composed of many small squares with similar colors, and these small squares are the smallest unit "pixels" that constitute the image. Pixels are divided into CCD pixels and effective pixels. Most digital cameras on the market now label CCD pixels instead of effective pixels.

Resolution: refers to the number of pixels represented or captured in a unit length. Like pixels, there are many kinds of resolutions.

The most common is the image resolution. What we usually call the maximum resolution of digital camera output photos refers to the image resolution in pixels. Red eye: When a digital camera shoots a human image in flash mode, the pupil of the human eye appears red spots in the photo.

In a dark environment, the pupil of the human eye will be enlarged, and at this time, the strong flash will be reflected on the lens through the fundus of the person. There are abundant capillaries in the fundus, and these blood vessels are red, so erythema is formed. Red-eye prevention is a function of the flash, which is to pre-flash once before the official flash, so that the pupil of the human eye is narrowed, thus reducing the phenomenon of red eye.

CCD: Translated as "electronic coupling element", just like the negative of a traditional camera. 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, we can still regard it as one of the important standards of phase machine grade. CMOS: "Complementary Metal Oxide Semiconductor".

The working energy is equivalent to CCD. AE lock: abbreviation for automatic exposure control device. AE lock is locked in an AE setting, which is used to manually control the exposure during automatic exposure to ensure the normal exposure of the subject.

SM flash card: smart media card, which is a storage medium. SM card adopts ss FDG/ flash memory card, which has the characteristics of ultra-small, ultra-thin and ultra-light, and its volume is 37 (length) 45 (width) 0.

76 (thickness) mm, weight 1. 8g, low power consumption, convenient upgrade, SM conversion card and PCMCIA interface, convenient for users to transmit data.

Optical zoom: when shooting at a distance, the object is magnified, because it depends on the focal length of the lens, so imaging does not affect the picture definition. Contrary to digital zoom.

Digital zoom: You can only reduce the size of the original image.

2. What are the basic terms of photography?

For ordinary people, photography is just taking pictures.

But for the same scenery, the same thing, I always feel that the effect is not as good as that of professional photographers. Only by knowing something can we use it better.

When buying digital cameras, we often hear people talk about ISO, but you know nothing about it. ISO is the sensitivity of the camera, and the best ISO can better restore the color.

But, what is the application? The higher, the more obvious the noise. Especially in the case of insufficient light, shoot by adjusting the sensitivity.

When the light is dim, the ideal effect can also be achieved by adjusting the light. Aperture is generally represented by f, which is a device used to control the amount of light passing through the lens.

The larger the F value, the smaller the aperture and the less light transmission. The smaller the F value, the greater the light intensity and the greater the light transmittance.

There is also depth of field, which refers to the range of the front and back distance of the scene that can be clearly displayed in the image. The focal length of the lens, the distance between the camera and the subject, and the light used will all affect the depth of field.

3. What does the camera term "wide angle" mean?

Wide viewing angle, covering a wide range of scenery.

The so-called wide viewing angle range means that at the same viewing point (the distance from the subject is constant), the scene is viewed with wide-angle, standard and telephoto lenses with three different focal lengths. As a result, the former shoots more up, down, left and right scenes than the latter. When the photographer has no retreat, it is difficult to take a complete picture (such as taking a group photo) with a standard lens of 50 mm ), using a wide-angle lens can easily solve the problem.

Furthermore, for example, shooting a vast Yuan Ye or a tall building in a city, perhaps only a part of the scenery can be photographed with a standard lens, which cannot show the breadth or height of the scenery. Shooting with a wide-angle lens can effectively show the open momentum of large scenes or majestic buildings.

Short focal length and long depth of field. Photographers usually rely on the short focal length and long depth of field of wide-angle lenses to bring the whole scene from near to far into a clear range of expression when shooting a wide scene.

In addition, when shooting with a wide-angle lens, if a smaller aperture is used at the same time, the depth of field of the scene will become longer. For example, if a photographer shoots with a 28 mm wide-angle lens, the focus is on a subject about 3 meters, and the aperture is adjusted to F8, then from 1 meter to infinity, it almost enters the depth of field.

It is precisely because of this long depth of field that wide-angle lenses are often used by photographers as fast-moving lenses with strong maneuverability. On some occasions, the photographer can quickly capture the picture by manipulating the wide-angle lens without focusing on the subject. You can emphasize the prospect and highlight the contrast between far and near.

This is another important performance of wide-angle lens. The so-called emphasis on foreground and far-near contrast means that wide-angle lens can emphasize far-near contrast more than other lenses.

In other words, the photos taken with wide-angle lens are closer and farther, which makes people feel that the distance has been widened and has a strong perspective effect in the depth direction. Especially when shooting with a super wide-angle lens with short focal length, the effect of being near big and far small is particularly remarkable.

Can be exaggerated and deformed. Generally speaking, it is taboo to use a wide-angle lens when the subject is exaggerated and deformed.

In fact, it is not necessarily undesirable for the subject to exaggerate and deform appropriately. Experienced photographers often use wide-angle lenses to deform the subject moderately and take some unusual photos of very inconspicuous scenes that people ignore.

Of course, using a wide-angle lens to express exaggeration and distortion should be based on the needs of the subject matter, and the second should be few and precise. No matter whether the theme is necessary or not, it is not worthwhile to abuse the exaggerated deformation of wide-angle lens and blindly pursue the bizarre effect in form.