What is a negative film? What is a reversal film? What is the difference between it and film?

Negative Film:

It is an image obtained after exposure and development. Its light and shade are opposite to the subject, and its color is the complementary color of the subject. It needs to be printed on the photo before it can be restored to the original image.

To put it simply, after the film we shoot is developed, the image we see is an inverted image, which is then enlarged or enlarged. The resulting photo becomes an image of the same color as the scene being photographed.

Take a black and white film as an example. On the negative film, the person's hair is white, but in fact, the white clothes are white on the film. Black; color film, the color on the film is exactly complementary to the actual color of the scene, for example: clothes that are actually red appear green on the film. Negative film is the most commonly used film for photography, whether it is black and white or color. < /p>

The negative film we usually use to take photos and develop it is a negative film. "Reversal Film":

The photo negative film we usually call is the negative film developed from ordinary film. The negative film is called a negative film. The color of the negative film is the reverse color of the actual photographed image. To make a photo, it needs to be re-exposed and enlarged or enlarged into a photo to become an image with the same color as the scene being photographed.

The so-called reversal film, also known as positive film and slide film, is similar to ordinary negative film in use (it is better to expose less than overexposed). The color shown on the negative film by the reversal film is the actual color, which can be directly Use, such as showing slides.

The reason why the film is called reversal film is that it is a negative image when it is first developed, and it turns into a positive image when it is developed again after being exposed halfway.

So the processing is different from the negative film. The reversal film uses the E-6 process, while the negative film uses the C-41 process.

The brightness and clarity are much better than the negative film, and the color is also very good. Excellent.

Whether it is negative film, positive film or reversal film, there are black and white film and color film.

Color reversal film is used for landscape photography. After the reverse development process, a positive image that is consistent with the scene's brightness and color can be directly used for projection and printing and platemaking.

The characteristics are: the contrast is larger than that of negative film, and smaller than that of positive film; the latitude is greater than that of negative film. Smaller, larger than positive film; the lowest density is small, and the film base is colorless and transparent.

Reversal film (i.e. positive film) is the general term for photosensitive films used to print photos, slides and film copies. /p>

It can print the negative image on the film into a positive image, so that the brightness or color of the image is the same as that of the subject. The color sensitivity of black and white positive films is limited to purple-blue light and the color sensitivity of color positive films. It is weaker than color negative film, so positive film is rarely used in photography.

Color positive film is used to print color projection copies (movies, slideshows). It is characterized by high contrast, low haze, and clarity. High sensitivity and low sensitivity.

Reversal film is divided into color and black and white. The reversal film we are talking about now is actually Color Reversal Film, which is often used in still photography.

It makes sense to call it a reversal film: the first stage of development is a negative image, and then the positive image formed by the color dye.

Reversal film is a kind of photosensitive film that can directly obtain a positive image by reverse processing after shooting.

Black and white reversal film can directly obtain a transparent film with the same dark image and the subject; color reversal film can directly obtain a transparent film with the same color as the subject. The color is true and bright, but the tolerance is limited. smaller. Due to its high-quality positive effect, reversal film is widely used in printing plates or slides. Professional photographers mostly use color reversal film when shooting advertising photos.

The reversal film can be played directly on a slide projector, but it is not troublesome at all to develop it into a photo. All digital printing shops can enlarge and print it.

For magazines, it is best to have normal exposure, because underexposure may cause the loss of dark details, thus affecting the printed effect.

Reversal film negative processing

Reversal film negative processing is to use reversal film to shoot and use C-41 to develop the film to turn the original reversal film into a negative film. .

(Of course, this is what you need to do when developing the film yourself. If you have reversal film, you can take it outside and develop it. Of course, there is no need for us to use PS)

The photos obtained by negative processing of reversal film are colorful and have high contrast, and the red, blue, and yellow colors of the scene are particularly exaggerated. Objectively speaking, negative processing of reversal film is more expressive in terms of color than negative processing. The exaggerated expression of color tone is inferior to that of color negative film, but in terms of gradation expression, reverse negative processing is inferior to negative negative processing, so it is very important to first establish the subject and then choose the film type.

Inverse negative processing is mainly suitable for portrait photography and some landscape photos.

Under the negative processing of reversal film, these two shooting themes have strong contrast, prominent subjects and bright colors, giving the photos a unique charm.

However, negative processing of reversal film is difficult and demanding in the processes of shooting, printing and enlarging.

Therefore, it is particularly important to choose reversal film appropriately when shooting.

When the light source is sufficient and the scene contrast is strong, you can use low-sensitivity reversal film to shoot.

50° and 100° reversal film can produce photos with saturated and vivid colors.

When shooting in an environment with weak lighting conditions, you can use reversal film at around 200° or 400°. High-sensitivity reversal film can reduce the contrast to a certain extent and make the photos slightly softer.

Exposure control and color correction during enlargement and enlargement are the most difficult for reverse-processed negatives. This is because currently photographers and photography enthusiasts use reversal negative-processing processes to develop and enlarge the negatives. Not many, many color enlargement shops are relatively new to this, and generally refuse to develop and enlarge. Most of the printers who accept development and enlargement have no experience in reverse and negative processing negative film printing, and the enlarged photos are seriously yellowish, blueish, greenish, etc. This is also a very normal phenomenon.

Generally, photographers are best to clearly indicate their needs, supervise the enlarging staff's operations on site, and use the "selection method" to select works that they are satisfied with.

Reversal film negative processing is also very difficult to enlarge in the production process, because the base color of this film is different from that of the negative film, and its exposure latitude is best controlled within ±0.3 seconds.

Reversal film negative processing has a good performance in landscape photography, and its advantages are also very outstanding in portrait photography. However, it is not easy to restore the skin color of people to normal, and the faces of people can easily turn yellow. However, due to the high transparency and high contrast of negative processed reverse film, the edges of the hair, eyebrows, eyes, lip lines, etc. of the character have a strong interpenetration of colors, which is similar to the edge dip left by a Chinese painter's heavy strokes on rice paper. Traces, with very exaggerated artistic effects.