1. Natural color negative film features

The structure of the natural color negative film is basically similar to that of the natural color film. Only the color scene of the scene is recorded by the complementary color of the silver salt and color coupler and the original scene color, and the resulting color negative image is recorded. With its plate making, the resolution of the color separation positive film is higher than that of the color photograph it is printing, and the tone is also more complete.

The tolerance of the natural color negative film is larger than that of the positive film, so the contrast is smaller than the positive film. If the contrast is too small, masks need to be made to enhance the contrast.

The colors presented by the negative film, although they are the complement of the actual scene, are still not easily recognized. It can be roughly understood from the following sections.

The pure yellow of pure purple objects in negative film; the yellow-orange color of violet-blue objects; the yellow-green color of purple-red objects.

The magenta color of a pure green object in a negative film, the red-orange color of a green-blue object, and the magenta color of a green-yellow object.

The cyan color of a pure red object in a negative film; the violet blue color of an orange object.

The brown color of the negative film is reddish or yellowish. Most of these colors are biased toward the achromatic system.

2. Natural color negative plate production

Due to the different types of negative films, the films of various brands have unique color tone characteristics. This kind of deviation can be corrected by professional scouring equipment and process methods during the unloading process, and it is more difficult to directly scan the negative film to restore the correct color space. Therefore, if the negative is the original manuscript, special attention should be paid to the authenticity of the color. The usual practice is: 1 first use a roller scanner to scan into RGB format at a higher resolution; 2 do inverse processing in Photoshop; 3 choose the film background as a white field, and completely expose the black field, so that the film can be eliminated. Chromatic aberration, then make appropriate adjustments to each RGB color channel. At this point you can refer to the CMYK value in the INFO tool, and finally do the color separation processing according to the normal photo. Most negatives can achieve satisfactory results after such adjustments.

Third, the second manuscript

The second manuscript is a reprint of various types of paintings into natural color prints as originals, also called indirect manuscripts. It is one of the original manuscripts that are increasing. There are two reasons why the second manuscript has become common: First, Chinese manuscripts, oil paintings, and other manuscripts. Due to the fact that the format is too large, copying the manuscripts, lighting is inconvenient, and some valuable paintings are not allowed to come up with treasured units. Take natural color positives, and then make plate; Second, with the popularity of electrical extensions, desktop pre-press systems and electrical extensions on the natural color positive plate is more favorable, and the original screen is too large, scan roller or platform can not be attached due to paste.

However, the quality of the second copy of the current remake has been poor, and the following problems are common. When copying, attention should be paid and compensation should be given to the process.

(1) If the second manuscript of the remake has a color cast, too thin, or a boring phenomenon, the second manuscript that has been remakeed due to exposure and improper processing will appear color cast, too thin and too boring, and some factories even The picture does not match. Reproduced in various drawings, especially the remake of Chinese paintings more shortcomings, Xuan paper color cast, light ink rhyme disappeared, coke, thick, heavy ink rhyme and grade, stamps and paste, inscriptions are not slander and so on. For this purpose, the deputy printing unit may be requested to place a color mark and a ruler next to the original when reprinting. In this way, when copying, the deviation in the second original photographing can be judged accordingly, so that it can be corrected in color separation.

(2) Reproduced secondary manuscripts have remanufactured secondary manuscripts when light and dark are inconsistent. High and low notes extend to the two ends, resulting in toes and shoulders. High-profile levels are lost, and low-key levels are merged. When remake, both cannot be taken into account. Therefore, it is required that all manuscripts based on high school tune should be lost during the remake, and that the tune of high school should be guaranteed.

(3) Reproduced uneven lighting The length of the large-sized screen strip reproduces most of the phenomenon of uneven lighting, and the phenomenon of deep and light in the middle. It is difficult to calibrate the electricity and the layout is not easy to correct. Therefore, before the color separation, it should be corrected evenly on the second original and then copied.

The secondary manuscript plate making process is the same as the natural color positive process, and will not be repeated here.