Some basic knowledge of photography!

Analysis:

Basic knowledge of photography

(1)-Classification of cameras

The camera has been around150th anniversary since it came out. Due to the changes of the times and the progress of science and technology, many types have evolved. If you want to get in touch with photography, you must have a minimum understanding of these cameras. The following are classified according to different classification methods for your reference:

(1) When taking photos according to the framing system, we see that the glass window of the shooting target and scope is the framing window.

1. Monocular reflection observer system: This is the most common camera observer at present. It uses the mirror behind the lens to reflect the picture captured by the lens, and then uses five mirrors to refract it, so that we can see the upright image from the viewer!

2. Perspective observer system: It has no so-called reflector and pentamirror, and the light directly enters our eyes through the observer. In close-range shooting, the imaging range of the negative will be different from that in framing, which is called parallax!

3. Binocular reflection observation system: This camera has an upper lens and a lower lens. The upper lens is the viewer, and the lower lens is the actual shooting. This system will increase parallax because of the different positions of the upper and lower lenses!

(B) according to the key system to distinguish

1. manual focusing: focusing is very important for a photo. The so-called focus is to adjust the focus ring and make the image clearly imaged on the film through the viewer's preview. If you adjust the focus ring by hand to complete the focus instead of the camera focusing automatically, it is called manual focus!

2. Auto-focus: The auto-focus camera uses the built-in motor to drive and adjust the focus ring without manual operation, but the auto-focus camera must cooperate with the auto-focus lens to play this function. If you are not used to it, you can use the automatic/manual switch button on the camera to change it to manual. If the autofocus camera is connected to the manual focus lens, you can only use manual focus. At present, relatively new electronic cameras, whether monocular cameras or binocular cameras (lenses cannot be replaced), are all of this type. Most of the old cameras belong to manual focusing.

(three) according to the size of the film used in the camera to distinguish:

1. 35mm film for camera-135 The camera film size is 24mm x 36mm, which is the most commonly used film for the public at present.

2. Camera using Brownie film-120 camera This camera can accommodate three different sizes of film: ~ 57mm x 57mm (6x6) ~ 56mm x 70mm (6x7) ~ 60mm x 69mm (6x9).

3. Camera with film cassette There are two specifications of camera with film cassette-126 camera-110 camera. 4. A camera with special film.

Basic knowledge of photography (2)- lens

The most primitive camera is a black box with a small hole. The light reflected by the scene passes through the small hole and then hits the photosensitive film. Because the light is emitted, it will continue to diverge through the small hole. The light originally emitted by points forms a circle on the photosensitive film, and the image is composed of many circles instead of points, which is naturally not clear enough. Therefore, a lens was invented to replace the circular hole. Monoconvex lens is the simplest lens, but it is only a little better than pinhole. If the image is not clear enough, it will cause aberration. If multiple lenses are combined together to minimize the aberration of each lens, it is a compound lens common to all cameras. Before introducing the lens, the term "focal length" must be explained. As far as a single lens is concerned, the distance from the focus to the center of the lens is the focal length. Generally speaking, the focal length of a compound lens is the distance from the focal point to the aperture position, but it is actually the distance from the focal point to the rear node of the lens. The rear node of the telescope head is far in front of the front lens and the wide-angle lens is behind the last lens, so it is different according to the lens design. Let's introduce a lens with a focal length difference:

1. standard focal length lens: its viewing angle is about 50 degrees, which is also the viewing angle that a person can see with one eye without turning his head and eyes, so it is also called standard lens. Generally, novices usually start practicing with the standard lens first, and then change to other lenses when the standard lens is not enough. The focal length of the standard lens of .75mm camera is mostly 40mm, 50mm or 55mm. 120 camera.

2. Wide-angle lens: named for its wide shooting angle, it is suitable for scenes with short shooting distance and large range, and can deliberately exaggerate the foreground to show a strong sense of distance. A typical wide-angle lens of a 35mm camera has a focal length of 28mm and a viewing angle of 72 degrees. The 50,40mm lens of 120 camera is equivalent to the 35,28mm lens of 35mm camera.

3. telephoto lens: suitable for shooting distant scenes. Small depth of field is easy to make subjects with blurred background stand out, but it is huge and difficult to focus on dynamic subjects. The telephoto lens of a 35mm camera is usually divided into three levels, namely, the medium focus1below 35mm and the telephoto1below 35-500. Cameras above 500 are called ultra-long focal lengths. 150mm lens of 120 camera is equivalent to 105mm lens of 35mm camera. Because the lens with long focal length is too bulky, the design of telescope head is available. By adding a negative lens at the back of the lens and moving the main plane of the lens forward, the effect of long focal length can be achieved with a shorter lens body.

4. Reflective telescope head: It is another design of the super telescope head, which uses a mirror to image, but due to design reasons, it is impossible to install an aperture, so the exposure can only be adjusted by the shutter.

5. Kyle lens: In addition to taking extremely close-up colossus photography, it can also be telephoto. Lens type focal length (mm) Photography angle Fisheye lens 8 180 Super Wide-angle lens10 20 94 24 84 Wide-angle lens 28 74 35 62 Standard lens 50 46 Medium-focus lens 85 28105 23135 65438 Length. 38+02 400 6 ultra-long focal length lens 600 4 1200 2 The above is the general classification of lenses, I hope it can be used as your reference!

Basic knowledge of photography (3)-Aperture

The lens of a camera has a device to control the amount of light transmission, which is called an aperture. The larger the aperture, the greater the light transmission. Small aperture can not fully describe the intensity of light acting on the film, and the distance between the lens and the film is also related to the focal length of the lens. If the focal length is small, the effect of light will be stronger. There is a term-aperture coefficient, which is the value obtained by dividing the focal length of the lens by the aperture diameter, and is expressed by F. For example, there are three lenses, A, B and C, and the focal length of lens A is 50. Lens B has a focal length of 35mm, a maximum aperture diameter of 17.5mm and an aperture coefficient of 35/ 17.5 = 2, which is also called f2 lens. The focal length of lens C is 100mm, and the maximum aperture diameter is 25mm, so the aperture coefficient is 100/25 = 4. We said f4 lens. The aperture of lens B is smaller than that of lens A, but the aperture coefficient is the same, so the intensity of light transmitted to the film is the same. The aperture size of A-C lenses is the same, but the aperture coefficient is different, so the intensity of light transmitted to the film is different. Apertures of all camera lenses have been standardized, that is, F 1, F 1.4, F2, F2.8, F4, F5.6, F8, F 165438 and F65438.

1. Control the penetration of light: the intensity of light passing through the lens to the film is inversely proportional to the square of the aperture coefficient, that is, the intensity of light acting on the film by two adjacent apertures is twice. F2 is twice that of F2.8, and F2.8 is twice that of f4.

2. Adjust the depth of field: The so-called depth of field refers to the range that the lens can clearly image before and after focusing, which is related to the focal length, aperture and distance of the subject. The shorter the focal length of the lens, the smaller the aperture, the greater the distance and depth of field of the subject, and vice versa. Therefore, as far as aperture is concerned, a small aperture and a large depth of field clearly show Ming Rui's sense of distance; Large aperture and small depth of field can make the subject stand out, showing the ambiguity of the subject outside the subject. It is worth mentioning that if the front and back scenes are clear, you should use a small aperture, but it should be small enough to cover the desired depth of field, not too small, and urine will be affected by diffraction, reducing its resolution!

Basic knowledge of photography (4)-shutter

The shutter of the camera is a mechanical device to control the exposure time. The shutter is often closed, which can prevent the exposure of the negative contained in the camera. Turn it on and off when shooting, so that the image light passing through the lens acts on the film. There was no shutter device in the early stage, but a lens cover was put on the lens. When focusing, remove the lens cover, cover the lens cover and attach the photosensitive film. When taking pictures, the lens cover is opened and then closed in an instant. Now the shutter has advanced to the point where the opening time is controlled mechanically or electronically. The shutter function is divided into the following two parts:

1. The length of the opening time controls the amount of light transmitted. If the brightness of the subject and the aperture of the lens are unchanged, the shutter opening time is long, the amount of light acting on the film is large, the shutter opening time is short, and the amount of light acting on the film is small. The length of shutter opening time is called shutter speed. In order to adjust the exposure, the lens of a lens shutter camera is equipped with a shutter speed adjustment ring, and the body of a focal plane shutter camera (more common) is equipped with a shutter speed adjustment ring. On the shutter speed adjusting ring, the shutter speed is divided into several stages. In order to adjust the exposure with the aperture, the shutter speed of every two adjacent stages is also two to one. The shutter speed classification of all kinds of cameras is standardized, that is, 4,2, 1, 1/2, 1/4, 1/8,1/5,1/. 1/500,11000, 1/2000, 1/4000, b, t. Shutter speeds faster than one second can only be expressed by denominator numbers, such as 2, 4, 8 ... B stands for bubble, which means that when you press the shutter button, the shutter will open, and when you relax, the shutter will close. T is the abbreviation of Time, which means that when the shutter button is pressed, the shutter will open and then close.

2. Exposure with aperture: Only when photography exposure is correct can you take photos with rich levels and clear details. In order to expose correctly, the shutter speed and aperture must be properly matched according to the film speed and aperture intensity.

Basic knowledge of photography (5)-exposure

Exposure value is the exposure value that matches the shutter speed with the aperture coefficient with a certain speed film. Exposure value's calculation method is based on ISO 100, so that the aperture coefficient f 1, the exposure of shutter speed in one second is zero, that is, EV is 0, and 0, 1, 2, 3, 4, 5 ... are arranged in sequence from 0, which means that the exposure is halved one by one, that is, the exposure of every two adjacent values is two. The exposure of exposure value at 1 is 0 1/2 times, which can be f 1.4 and 1 sec. The exposure with exposure value of 2 can be f 1.4, 1/2 seconds or f 2, 1 second. The same exposure value can have many different combinations of shutter speed and aperture coefficient, and its exposure is the same. The exposure value of F 1 1,1/60s and F8,1/25s and F4,1/500s are all 13, indicating that the exposure is equal. When shutter speed and aperture coefficient can be combined in different ways to produce equal exposure, it is called exposure equivalence law. The following is the exposure value based on ISO 100/2 1. You can compare it: f1.4f2.8f4f5.6f8f1f16f221sec12345678 91/22345678 9 65438. 4 3 4 5 6 7 8 9 10 1 1 1/8 4 5 6 7 8 9 10 1 1 12 1/ 15 5 6 7 8 9 / kloc-0/0 1 1 12 13 1/30 6 7 8 9 10 1 1 12 13 14 1/ 60 7 8 9 10 1 1 12 13 14 15 1/ 125 8 9 10 1 1 1 2 13 14 15 16 1/ 250 9 10 1 1 12 13 14 15 16 / kloc-0/7 1/ 500 10 1 12 13 14 15 16 17 18 1/ 1000 / Kloc-0/ 1 13 65438 Therefore, when we want to shoot a brighter object than medium gray, we should increase the aperture or lower the shutter speed. For example, when shooting a white wall, we should increase the exposure by one or two times according to the value measured by the camera, so that the wall will appear white. When you want the subject to be darker than medium gray, narrow the aperture or increase the shutter speed. For example, when shooting a black wall, you should reduce the exposure by one or two times according to the value measured by the camera, so that the wall will appear black!

Basic knowledge of photography (6)- filter

For some purposes in photography, it is necessary to use a lens to block some wavelengths of light, so that it does not enter the camera through the lens, or to limit the components it passes through. This kind of lens is called a filter, also called a color filter. Filters can be roughly divided into six categories:

(1) Contrast filter: A filter used in black-and-white photography, which changes a certain tone of the subject to improve the contrast, also known as contrast filter. The application principle of contrast filter is to use a filter that passes through a certain color in a photo when the tone is light, and a filter that absorbs the light of that color when the tone is dark. For example, if you take a picture of a red flower and a green leaf, if the brightness of the red flower is similar to that of the green leaf, there is almost no difference in the tone of the photo. You can use a rainbow filter with red light to lighten the hue of red flowers. Generally speaking, there are six important contrast filters, each of which is divided into three levels:

1. Red filter: absorbs green, blue and purple, mainly passing red, followed by orange and yellow.

2. Yellow filter: blue-purple absorption, mainly through yellow, followed by red, orange and green.

3. orange filter: between the red and yellow filters.

4. Green filter: absorbs red, orange, blue and purple, mainly through green, followed by yellow.

5. Yellow-green filter: between yellow and green filters.

6. Blue filter: absorbs red, orange, yellow and green, mainly through blue, followed by purple.

(2) Ultraviolet filter: UV for short, ultraviolet is invisible light, but the film has a strong sense of it. Therefore, when shooting scenery, ultraviolet filters should be used to absorb the ultraviolet rays in the distance, so as to reduce its influence on the negative film and enhance the clarity of the image. Also known as skylight filter, it is also the nature of ultraviolet filter.

(3) Neutral color filter: ND for short. Neutral color filter has the same absorption rate for all kinds of light and is used to reduce the amount of light passing through the lens. When the minimum aperture or the fastest shutter is used and overexposed, a neutral filter is needed to reduce the exposure value. There are three types: double, four and eight. The so-called multiple is only the exposure multiple.

(d) Polarizing filter: referred to as PL for short, it is composed of many tiny crystals with the same direction, and the light reflected from the sky, water surface and non-metallic smooth surface at a certain angle will be polarized. If a polarizer is installed on the lens, these reflections can be controlled, eliminated or weakened to show the texture of the object. It has the following four functions:

1. Control the hue of the sky: If you want to deepen the hue of the blue sky in color photography, you can use a polarizer. The hue of trees and water will be enhanced by absorbing some reflections.

2. Control the reflection of objects: It is ideal to control the light reflected by a nonmetallic smooth surface with a polarizer, such as shooting the goods in the window or the underwater scenery across the water surface, in which it is more effective to tilt the reflecting surface by about 30 degrees.

3. Improve the chroma.

4. Replace the neutral color filter: the exposure multiple of the polarizing filter is close to four times ND, and the former can replace the latter.

(5) Infrared filter: Absorb all visible light except ultraviolet rays, and only let infrared rays pass through. Committed to infrared film photography.

(6) Color temperature balance filter: the color film is designed for the standard color temperature, so that the color sense and speed of the blue-green-red three-layer emulsion can be balanced, thus achieving color balance. However, the color temperature of sunlight is different from morning to dusk, so is the color temperature of cloudy and sunny days, and the color temperature of light is different due to voltage. When the color temperature of light source does not meet the requirements of film color temperature, color cast will appear, and color temperature balance filter is needed.

Basic knowledge of photography (7)-color temperature

Regarding color photography, the color temperature will affect the feeling of a photo. The photos taken in the morning or evening will be red, and the photos taken by tungsten lamp will be yellow. These phenomena are all caused by color deviation because the color temperature at that time could not reach the color temperature standard of the film. Physically, when an object called a complete blackbody is completely heated, its temperature rises and it begins to turn red in a red-hot state. If heating is continued, it will turn white in a white-hot state. In the red heat state, the radiant energy of the light source is low, and the wavelength of light is red, while in the white heat state, the radiant energy of the light source is high, the wavelength is short and the blue component is many. The higher the temperature of a luminous object, the whiter the color of light, and the lower the temperature, the redder the color of light. For the same tungsten lamp, the light at low voltage is redder than that at high voltage.

Used in photography, color temperature is the color component of light emitted by luminous objects from red to white. The degree of color temperature is expressed by k, that is, the temperature is +297 degrees Celsius. When the color temperature k number changes, the composition of blue light does not change with the same amount, so it is not very convenient to convert when adding a filter to adjust the color temperature. So there is the design of DM value. The calculation method of DM value is100000 times of the reciprocal of color temperature K, so the higher the color temperature, the lower the DM value, and the lower the color temperature, the higher the DM value. The advantage of using DM value is that when the DM value changes, the blue component of light changes by the same amount, so it can be determined by the difference between the DM value of film color temperature and the DM value of light color temperature.

For example, the color temperature standard of Sunglow film is 19DM (equivalent to 5400K). When used in the case of light color temperature 14DM (equivalent to 7000K), the difference between them is 5 mm, and the red R5 filter is used to reduce the color temperature.

Color temperature of time light source K # color temperature DM of light source

At sunrise, 50 in 2000

20 minutes after sunrise or before sunset 2 10048

30 minutes after sunrise or before sunset 2400 42

40 minutes after sunrise or 29: 35 before sunset

After sunrise or before sunset 1hr 3500 29

2 hours after sunrise or 2 hours before sunset 4500 22

3 hours after sunrise or before sunset 5400 19

The average sunshine at noon is 5400 19.

Cloudy day 6500-8000 15- 13

Fluorescent lamp 7000 14

Electronic flash 5500 18

Blue flash bulb 5400 19

White flash bulb 3800 26

Floodlight for photography 3400 29

Household 500W bulb 3000 33

Tungsten lamp for photography 3200 3 1

Household 100W light bulb 2900 35

The color film is designed according to the color temperature of standard lighting. The standard of sunshine film is 5400K at noon on sunny days, the standard of floodlight is 3400K for A-type positive film, and the standard of tungsten lamp is 3200 K for B-type positive film and L-type negative film. When the color temperature does not reach the color temperature standard of the film, you can't shoot a pure color film, so you need to use the color temperature balance filter (LB filter) to adjust it! LB filters are divided into about 4 series:

80 series (heating) 8 1 series (cooling) 83 series 85 series (cooling)

80A 3200 K ->5500 K

80B 3400 K ->5500 K

80C 3800 K ->5500 K

80D 4200 K ->5500k 8 1a, 8 1b, 8 1d, 8 1ef will increase the color temperature from 6000K-8000K-5000K to 5500k-> 3400 K.

85B 5500 K ->3200 K

85C 5500 K ->3800 K

Basic knowledge of photography (8)-Film types

(1) color positive film:

Kodak

(1)k- 14 (need to be developed abroad) Kodak Chrome 25(PKM)- the king of color positive film, with extremely fine particles, high resolution and a slight magenta tone, suitable for shooting white people. Kodak Chrome 64(PKR)- Multi-purpose negative with the same characteristics as PKM. Kodak Chrome 200(PKL)- High-speed negative with the same characteristics as PKM.

(2) E-6 ektachrome64 (EPR)-Fine particles, high resolution, slightly similar to Kodak color series, but slightly insensitive to green, not suitable for the scenery. EKTACHROME 100 PLUS(EPR)- strong color performance, the rest are the same as above. Ektachrome P800/1600 (EES)-High-speed film, which can be used at 400, 800 and1600 degrees.

Mount Fuji

Fuji chrome Velvia(50 RVP)- With its extremely bright colors, extremely fine grains and extremely high resolution, it has replaced PKM as the king of the next generation of color positive films, and has outstanding performance in purple, which cannot be correctly restored by ordinary negatives, and also in green and blue. Fuji chrome 100d(RDP)- a film with moderate sensitivity and normal color reproduction, is widely used. Fuji color 400d(RHP)- High sensitivity negative with good color. Fuji chrome 1600d (RSP Ⅱ)-ultra-high-sensitivity film, which can be used at 400, 800 and1600 degrees. In addition, Fuji color 100D(RD) is generally negative. Generally speaking, Fuji's films are natural in color and suitable for general use, while Kodak's films are more selective and suitable for special use.

(2) color negative

Kodak

EKTAR 25(PHR)- Color negative with the most systematic particles and the highest resolution. Ekta press GOLD 100(PPA)- Special film for reporting photography, with poor color performance. Ekta press GOLD 400(PP- features as above, PPC is the only color negative that can be exposed to light. Ekta press GOLD 1600(PPC)- same as above. There are also Kodakin100,200,400 and other general negatives.

Mount Fuji

Fuji color REALA (100)- the most normal negative of color sensitivity. Fuji HG( 100) usually uses negative film. Fuji super HG 400- high-speed film, the color is quite beautiful. Fuji color super HG 1600- super high-speed film.

KONICA

SR-V 100- generally negative. SR-G 3200- color negative with the highest sensitivity ever. The characteristics of color negatives are not as obvious as positive ones, because developing a photo requires quite a few steps, among which the print shop plays a very important role.

(3) Black and white film:

Kodak

Technology Pan 24 15(25)- Black-and-white film with the lowest sensitivity, extremely high resolution, extremely wide black-and-white tone and extremely fine particles, which is called the king of black-and-white film. T-MAX 100(TMX)- high resolution and excellent tone, but the grain is a little rough. T-MAX 400(TMY)- High sensitivity, good sensitization and coarse particles. T-MAX p 3200(TMZ)- The particles are thinner than the negative, and the sensitization can reach 25,000.

Mount Fuji

Neo panss( 100)- the most common black-and-white film, with fine particles, but poor tone performance. Neo pan 400 Professional- fine particles, wide color tone and slightly low contrast. Neo pan 1600 Professional- ultra-high-sensitivity negative with coarse grains. Ilford: Pan F (50)-Very fine particles, extremely high resolution and slightly different color sensitivity. Pan 100- Fine particle FP4( 125)- Beautiful tone, but slightly coarse particles. HP5 PLUS(400)- Fine particles, wide color tone, slightly lower contrast, which can improve the sensitivity to 3200 400 DELTA- Fine particles, beautiful color tone, which cannot improve the sensitivity.