photographic film

The main differences between them are: the brightness and color of the image on the negative are opposite to the actual scenery; The same is true for reverse films. If the main purpose of shooting is to develop photos, you should choose the most commonly used negative films. Reverse film is mainly used for making slides or printing plate making. Another difference from negative film is that it is more difficult to develop photos with reverse film. At present, there are very few photo agencies that can develop reverse films, and even fewer can develop photos directly with reverse films. There are only two or three in Beijing, but there are none in most provinces in China, and the price of developing photos directly with reverse films is higher (3-4 times more expensive than developing photos with negative films in China). If you copy a negative with a reverse film first, then use it to develop the photo, it is ok, but it is still more troublesome.

The English difference between the two is that the film is colored after the English brand, such as Fuji color negative. The reversal film changes color to chromium, such as Ektachrome (Ekta reversal film of Kodak Company). There is a simpler identification method, which is informal but effective-you can always find the words C-4 1 on the negative box or metal cassette; E-6 can always be found on the negative box. But they are all in small print, and they are not in conspicuous places. By the way, it is worth mentioning that the negative film has a large exposure latitude, and generally, the negative film within the range of more than 3 files and less than 2 files can develop good photos; However, the reversal film generally has only a tolerance of half scale and half scale, and beyond this limit, the image effect will be obviously worse.

It is customary to think that only professional photographers can use reverse films, but it is not. In this regard, we might as well imagine: in a slightly lingering and gloomy living room, Chopin's piano is the background music, the slide image gradually fades out of the wall in the smell of old whiskey, and the conversation between friends is high and low, sometimes sparse and sometimes slow-whether it is a souvenir photo or an artistic photography, it will be a very meaningful process, and it will be more delicious than playing videos and looking at photo albums. Why don't you try selling some reverse films? The price of the slide projector is only 1000-8000 yuan.

2 sensitivity

Depending on the sensitivity to light, film also has sensitivity. The sensitivity of this kind of film is 21100, which is often seen on film boxes. Where 2 1 is a German unit called "Ding" and 100 is an American unit called "Degrees". Later, when they were combined, they became the sensitivity unit of international standards. But now most movies still take "degree" as a conspicuous symbol. It is worth remembering that every increase or decrease of 3 degrees means that the sensitivity is doubled, so it is necessary to decrease (increase) the aperture or decrease (increase) the shutter time by one level when shooting. Commonly used are 18/50, 21100, 24/200, 27/400, 30/800, 33/ 1600. The lower the film sensitivity, the better the image quality; But it must be at the expense of extending the shutter time. The longer the exposure time, the easier it is to take photos. The high-sensitivity film is naturally the opposite of the low-sensitivity film. In addition to professional photographic equipment stores, most of the color negative sold in the market is 21100, and the film with this sensitivity is the cheapest, whether it is negative film or reverse film. However, it is not uncommon for stalls in tourist areas to sell fake films, and it is difficult for non-professionals to distinguish between true and false.

3. Lighting type and daylight type

Only color film can be divided into light type and sunlight type, and this distinction is particularly important in reverse film. Optical film is suitable for shooting under incandescent lamp (high wattage is better). If you shoot in the sun, the image will be severely blue. Sunshine films are suitable for shooting in the sun, and if they are shot in the light, they will turn yellow seriously. However, whether it is light film or sunlight film, it will be difficult to take photos with normal color under the so-called fluorescent lamp. Because fluorescent lamp is not continuous spectrum, it is not easy to correct. The optical film box must be marked with the word tungsten; The sun cursor has the word daylight, but it is generally not as eye-catching as the former. However, no matter what light source, the flash must match the sunlight; Photos taken by direct lighting with flash are often dull and tasteless, so try to avoid flash lighting. Negative film does not strictly distinguish between light type and sunlight type because it is easier to correct color in the process of developing photos.

4 Professional and Amateur

Negative films and reverse films can be divided into professional films and amateur films. Professional films have better imaging quality than amateur films, but the price is much higher. They should be kept in the refrigerator for a long time. Professional (some films have an S after this word) is the logo of professional films, and amateur films are generally not marked. Of course, if you have money, you should buy a professional film.

5. A movie that can't be developed in China.

The vast majority of Kodak reversal films sold and used in China should be "Kodak Ektachrome". Kodak's top professional reverse film is "Kodakchrome". Although this kind of film is good, it can only be developed in the United States and a few countries. In foreign countries, the price of this kind of film includes two kinds: printing fee, mailing fee and no. This film can't be developed not only in Chinese mainland, but also in Hongkong. Because it uses the "foreign couple" washing process, which is a patented process strictly kept secret by Kodak Company, it has never spread abroad, and there are certain environmental reasons, which leads to its poor reputation. But professional photographers in Europe and America often use this film. In short, whatever the reason, you must be careful when you come across this kind of film. Some films are shot in China and developed abroad, which is really troublesome.