The Key Technology Of Laser Paper Sliding Drawer Box Processing Backlight Photos Before Press

The key technology of Laser Paper Sliding Drawer Box processing backlight photos before press

 

Photo prepress processing is the guarantee of printing quality. In the pre-press processing, the original photo is affected by the shooting technology, equipment, environment and other factors, so that the original photo has different degrees of defects. In addition, different photos have different artistic styles and effects, which requires prepress production not only to correct the shortcomings of the photos, but also to deal with the artistic effects pursued by the author as much as possible. Light is the lifeblood and soul of photography, according to the characteristics of light in photography, photos can be divided into downlight works and backlight (including side backlight) works. The light source is in front of the subject (including the side front). Backlight (or side backlight) shooting, the light source is behind the subject (or on the left and right side of the shooting point). Inverse light photography can enhance the texture of the subject and the atmosphere of the color, enhance the visual impact force and the depth of the picture, so that the photo is rich in color and charm, strong contrast and strong sense of space. In backlight photography, the light method is one of the most effective photographic creation methods, backlight photos can make ordinary objects into attractive images, the mediocre things to beautify, so it is a common method in many photographic art. However, due to the existence of high contrast and many changes in backlight photography, the main parts are mostly in shadow, and the ideal shooting effect is not easy. Photography works often have dark light on the front side, and the light quality is not ideal, so that the tone contrast is large, the light and dark levels are not ideal, and there are shortcomings that the color texture of the front side of the object is difficult to fully achieve. Some inverse light works photography due to the impact of stray light, unnecessary spots or fog light and shadow in the picture, directly affecting the level and tone of the performance. All of these require the production personnel to master the characteristics of backlight photos, improve their artistic cultivation and aesthetic perception, make full use of advanced pre-press equipment and technology in the pre-press production and processing, and accurately grasp the key technology of Lin Qi's backlight photos before watermarking in the Fujian Academy of Agricultural Sciences Information Institute to process the style of backlight works. Select the best process method according to the photo and printing characteristics to improve the production quality. To sum up, we should pay attention to the following aspects.

 

First, grasp the tone of backlight photography works

Because the backlight works pay attention to light, the tone changes greatly, and can form a variety of different color tones. In a large number of backlight works, some are mainly warm colors, and some are mainly cool colors. In addition, some of the color of the picture seems to be some color, in fact, the author deliberately pursued, so it can not be considered to be color, so, in the reproduction of the accurate picture tone, is the premise of doing a good color copy. For example, the backlight works with characters as the main body should be reasonably controlled when copying the color base of the characters, and the color of the characters should have an appropriate sense of brightness, but it must be consistent with the overall tone of the picture to achieve harmony and unity. In this way, through color reproduction, can truly reflect the characteristics of backlight works.

 

Second, pay attention to the light processing of backlight photography works

Backlight photography is characterized by the full and accurate use of light, the original manuscript is very much concerned with light, therefore, pre-press production to deal with the beauty of light, first of all to distinguish the direction of the main light is side backlight, or backlight. Distinguish between light surface, medium surface and dark surface. The brightness of the intermediate surface shall not exceed or be flat with that of the receiving surface; The brightness of the dark plane cannot exceed or equal the brightness of the middle plane. Take photos of people, for example, if the dark face is inverted or flat, then even if the skin color is handled well, it still gives people a feeling of discomfort, so you can not simply emphasize the bright color and lose the relationship between the light and dark faces of people. Copying should master the following points: (1) pay attention to the light effect of the overall picture, to have a strong sense of light. Look at the plate, look at the contrast. The color of the light surface can not be flat and full, and the dark tone should be deep; (2) The highlight should be bright, and the highlight point should be concentrated. The highlight part of the picture has the strongest sense of light, the highlight brightening area should be small, the smaller the surface area, the more concentrated the light, the highlight can be illuminated. The extreme highlight of the network, shallow and medium tone level should be rich, in order to highlight the brightness of the highlight; (3) To protrude the main light. Some manuscripts are cluttered with light, confused between positive light and backlight. It is necessary to make local corrections on the original manuscript, consciously focus the main light on the central part of the picture, and compress the four sides of the astigmatism, so that the line of sight is concentrated, the theme is highlighted, and the artistic effect is enhanced; (4) Deal with the reflection. Note that the crossing line of the character's face should be obvious when the dark side turns to reflect, and some reflections need artistic processing.

 

Third, emphasize the sense of light in the picture

Photography is the use of light to describe the shape, color, tone levels, perspective and texture of the subject. Therefore, in the reproduction must pay attention to the light characteristics of the backlight works. The photos with different light angles (including the use of color light) should be analyzed and studied in detail. In the reproduction, it is necessary to grasp the changes in the light of the picture, so that the bright part of the painting should be illuminated, the dark place should be dark, and a certain contrast should be maintained to achieve clear scenery, rich layers, and a good sense of perspective and the effect of standing body. For example, in a close-up work, large areas of rich tones are backed by small areas of bright tones. And this small area of bright tone, in the picture and play the role of drawing the dragon's eye. If you give up or ignore the use of this small area of bright tones in the reproduction, it will make the picture gray without light sense, and lose the charm and style of the character's backlight works.

 

Fourth, grasp the performance of texture

Backlight works also have an ideal expression for the surface texture of objects. Therefore, the reproduction of texture should also be emphasized in the reproduction. For example, for a snow scene, in the replication of the contrast to consciously strengthen the tone contrast, improve the brightness level and sub-brightness level, and maintain a certain amount of color, in order to facilitate the quality of snow performance. For other types of backlight works, we must also pay attention to the appearance of the texture, otherwise, we will lose the inherent characteristics of the backlight works.

 

Fifth, the color should be thick and bright

The backlight works have the characteristics of rich tone, high color saturation, strong density contrast, etc., while the printed matter is restricted by various specific conditions, resulting in the reproduction of contrast contrast, color saturation, gloss and other aspects are not as good as the original. Because of this, in the reproduction of the color of the various plates to use enough, and pay attention to the bright color and level of strength of the performance, to reflect the backlight works of thick and bright color characteristics. For example, in a backlight work with a white kitten as the main body, the main body is in a dark and cool tone, the front side of the cat is illuminated by warm light, the edge of the cat presents a cool color outline, and the front side of the main body is a middle tone that echoes the cold and warm, forming a rich and thick picture of color changes. For this, two points should be paid attention to when copying: First, on the basis of ensuring the background color amount of thick, handle the relationship between the main body, outline light and the background color amount, to prevent the main body from jumping out of the painting due to too bright, affecting the harmonious and unified effect of the whole picture; The second is to pay attention to the performance of the color vividness of the main gradient wheel profile to enhance the color vividness of the entire picture and achieve a pleasing reproduction effect.

 

Six, pay attention to the setting and adjustment of the middle tune

Controlling the amount of color used in the middle tone is very important for the production of backlight works, which can stabilize the amount of ink used in light and dark, and avoid the phenomenon of shallow or deep tones. In the reproduction of color reverse film, it is necessary to keep the bright tone color bright and fast, the middle tone is rich and the dark tone is thick on the basis of the appropriate compression of the step tone, and the amount of ink used in the dark tone should be compressed. In the reproduction of color photos, it is necessary to consciously improve the clarity on the basis of controlling the tone, especially to emphasize the intensity of the bright tone. In the case of side backlight works with large surface, few level of tone and color saturation, the color quantity should be appropriately increased on the basis of maintaining the level to achieve a harmonious and balanced reproduction effect of tone. The setting and adjustment of the middle tone must first meet the visual habits of the human eye. A portrait photo, whether it is light or backlight, medium tone is light, skin color is light and thin, medium tone is dark, skin color is dark and dark, even if more than 5% of the dot value is light and dark, it will give people an uncomfortable feeling.

 

The key to three-point calibration of backlight (side backlight) is to control the midpoint. In addition to the middle point control with the gray ladder rule, it is more important to choose a piece of the face as the control point, the trick is to choose which piece of the face as the control point, how to scientifically convert the density into the dot value. According to the operation experience, the forehead should be used as the intermediate control point, with the dot value of the red version as the benchmark, the density value of the forehead part of the reverse film is 1.2, which is converted into a dot area of no more than 50% and controlled at 45% ~ 48%. When the backlight face density is larger, the secondary highlight is used as a white field setting point, the layer curve is lightened by 10%, the density value is scaled with the largest black field, the middle and dark levels of the face are fully displayed, the black version level curve is steepened, and the black version is used to open the hair and the dark level of the face. If the face brightening density is weak, the white field calibration density value should be small to deepen the color level of the brightening tone. The black field calibration density is smaller.

 

According to the facial density of the portrait manuscript, it is divided into three categories: ① normal exposure. Density contrast standard cis photo, side backlight, the face body is in bright tone, medium tone, it is proportional to the brightness, is in the best visual brightness range. Generally, by setting the density value of the highlight and dark tone and the corresponding level curve and color correction, the level and color change of the original skin color can be better reproduced without any modification and adjustment. ② Overexposure. High profile photos with small density contrast, the main part of the face is bright and thin, and the brightness is high, and some deepening adjustments are needed. To reduce the brightness, close to the standard brightness, in order to achieve a better tone contrast and visual brightness effect. ③ Underexposure. The backlight photos with large density contrast, the main part of the face is dark and deep, and the brightness is low, and some adjustment needs to be made to reduce and improve the light. On one side, on the basis of the automatically set high light and dark tone density values, manually add some set density values, which needs to lose some high light layers and compress some dark tone layers; On the other hand, the curve of the medium to the medium dark area is pulled down, and the required dot value is reduced by 5% to improve the brightness and move closer to the standard brightness to achieve a better step contrast and visual brightness effect.

 

Seven, control the tone contrast

A wide range of density and rich color changes are another feature of backlight works. In the case of limited print density range (about 1.8) and color change is far less than the reverse light works, the process conditions of plate making and printing should be made full use of the dark tone of the black plate, and the level and color amount of the bright tone should be controlled, so as to make the color gamut of the replica wide and vivid. Copy side backlight, on the basis of controlling the stability of the middle adjustment, it is necessary to appropriately make the step tone longer to facilitate the three-dimensional sense and perspective effect of the scene in the picture. Especially scenery works, it is very necessary to make the step tone longer, which is more conducive to the performance of the characteristics of the side backlight scenery works. In addition, on the basis of maintaining a good intermediate adjustment in the replication, the brightness of the brightness should be appropriately improved, and if necessary, some local bright points can be made into a network to enhance the crystal sense of the picture. On the basis of maintaining layers, the color should be thicker to help strengthen the sense of space and three-dimensional sense of the entire picture, maintain a good brightness ratio and color contrast, and achieve a pleasing reproduction effect. In the actual work, for the works with relatively flat brightness, the color quantity should be improved on the basis of maintaining clarity; For dull works, the color amount of a certain color plate should be appropriately reduced while maintaining a moderate tone, so as to obtain a good reproduction effect.

 

Eight, the calibration points of various versions

Some side backlight, backlight figure images, the face of the dark area is large, high color density, the color is yellowish brown or red brown. When calibration, the dot area of the yellow and red version is more than 80%, or even 90%, which is close to the dot area of the deep primary color (100%). Because the dot in this area changes greatly in the color value when printing, even if it is printed according to the standard ink amount, the color of the printed skin will be red, the "fire", and then the deep primary color is unsaturated and graded, and it is difficult to take into account the two when printing. If the printing brush takes into account the color of the skin, the amount of ink is small, the skin color can be, but the deep primary color is unsaturated; If the printing takes into account the deep primary color, the amount of ink is enough, then the dark skin color is red. Therefore, this operation point is to take corresponding measures for this situation. Such color separation film can achieve good reproduction effect, and the printability is good. If you encounter some of the original manuscript itself there is a gap between grades, then the color separation calibration should be based on the dark skin color, and the red version is controlled at about 75%. When the amount of deep primary color is not enough, this region is selected for local deepening treatment to open the distance between the two. Such a color separation can not only make the dark skin tone moderate, but also take into account the saturation of the deep primary color to achieve the best of both worlds.

 

In short, in the pre-press production of backlight photos, we should carefully analyze the original manuscript to see whether the color is biased, the level, clarity, color saturation, etc., is good, fully understand the author's creative intention and the artistic effect they want to achieve, and carry out the necessary processing and upgrading of the original manuscript according to the advanced pre-press equipment. Thus, the true artistic effect and printing quality of the work are fully reflected.