What does the term "reversal film" mean in photography?

"Reversal Film":

It is divided into color and black and white. The reversal 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 creates a negative image, and then the color dye creates a positive image. 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 as the subject; color reversal film can directly obtain a transparent film with the same color as the subject. The colors are true and bright, but the tolerance is small. 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.

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

Reversal film negative processing is to use reversal film to shoot, and use C-41 to develop the film, so that the original reversal film becomes a negative

type film. (Of course, this is what you need to do when you develop the film yourself. If you have reversal film, you can just 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 subjects 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 enlargers who accept development and enlargement have no experience in reverse and negative processing film enlargement, and the enlarged photos are seriously yellowish, blueish, greenish, etc. This is also a very normal phenomenon. Generally, it is best for photographers to clearly indicate their needs, supervise the operations of the enlarging staff 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 during 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.