How to analyze the manuscript

First, the transmission of the original

We made the plate-making staff to call the original of the transmission the original film, and the photography staff called the transmitted film the reversal film, and some people called it the slide.

The reversal films currently on the market are: Kodak Kodak, Fujifilm Fuji, Agfa Agfa. They are all coated with oil-soluble dyes.

The reversal film is divided into daylight type and light type according to the color temperature requirement. The daylight color temperature is 550K, and the light color temperature is 3200K.

The reversal film has a variety of low-to-high sensitivities, and the sensitization index currently has two types of calibrations on the market; ASA and DIN.

The ASA program is based on the United States calibration, and has photographic plates such as ASA 25, 50, 100, 200, 400, 800, etc.

DIN is based on the German calibration. Our domestic reversal film and film sensitivities are based on DIN. For example, DIN 21° is the same sensitization index as the Kodak ASA100. DIN 24° (determined) is the same sensitization index as Kodak ASA200.

Every doubling of the ASA index doubles the speed of light. The DIN index differs by 3 (determined) and the photospeed is twice as fast. The DIN index differs by 3° (definition) and the photospeed is twice as fast.

Reversal films are also divided into amateur and professional models. The reversal film was rinsed with E-6 kit and the development temperature was 38°C.

Professional reversal film such as Kodak EPP professional reversal film must go to the professional rinse shop flush.

The quality of the reversal film has a close relationship with the photographic equipment, the photographer's skill, the ability to grasp the color temperature, the exposure accuracy, and the strict conditions for washing (including water quality). It's not as simple as taking photos of life.

We analyze the situation of color negative film and color reversal film from the exposure.

Exposure refers to the film's ability to record images over a range of light intensities. Exceeding this range of details, the human eye may not be able to record on film, although it may be visible. The purpose of estimating exposure for photography is to adjust the range of recordable light to the details of a very useful subject. If the exposure is too strong, the details of the shadow can be recorded, but the strong light is lost. However, if it is too weak, only the strongest part of the lighting can be recorded.

1. Color negative: A typical relative exposure logarithmic curve of a color negative if normal developed.

Logarithmic curve 1. Dark 2. Density 3. Bright 4. Less light 5. Exposure 6. Light more 7. Blue 8. Green 9. red.

Note the difference between the normal exposure and the poor one, the second negative underexposed film, and the negative one exposed. In these cases, the exposure can be corrected at the extended printing stage.

A. Low two; B. Low one; C. Normal; D. High grade

2. Color reversal film: color reversal film through the normal development to see the typical relative exposure logarithmic curve, pay attention to the exposure of the red density is bound to be deeper than the blue (darker).

If we take the color reversal film curve as correction in the printing plate class, the color balance of the normal exposure part on the negative film will be destroyed.

We analyze the situation of color negative film and color reversal film from latitude.

The concept of latitude: The ability of the photosensitive material to correctly express the full brightness difference of the subject is the latitude of the photosensitive material.

The lower the contrast, the greater the latitude of the exposure.

The color negative film can still obtain a very satisfactory image at least when the aperture of the difference between 1 and 1.5 is over or underexposed. Even the poor 2 to 3 apertures do not necessarily have to be discarded, but there are significant flaws in the highlights or shadows.

Color reversal films, especially high-sensitivity reversal films, require exposure in the "correct" aperture of 1/3 to 1/2 stops. If there is a difference, the image will not actually meet the professional standards.

The size of the reversal film is determined based on the area of ​​the camera's back.

The 135 color negative film (24 x 36 mm) has 24 sheets and 36 sheets in two sizes. From civilian to professional, their prices differ by a factor of 4, such as Kodak 135 color negative film ASA100 RMB 20, flushing 4 RMB, reversal film ASA 100 RMB 80, and washing 16 RMB.

120 color negative film and reversal film, according to the back of the camera (replaceable) has a 4.5 x 6cm 16-flavored back. 6×6cm12 backs. 6×7cm10 backs. 6×9cn8 backs.

The 8×10 inch and 4×5 inch professional single reversal films are contained inside the cassette. Each cassette contains a front and a back. Are taking pictures with a professional camera. There are Lin Yufu and Xian Na and other planes.

Source: PACK.CN