How to get the most popular outlets

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How to get the desired point

if you want to win customers, you must make high-quality images, and calibrating the imagesetter is a crucial part. It is difficult to obtain high-quality points with an uncalibrated Imagesetter, and it is not difficult to calibrate the imagesetter as long as there are appropriate tools. In this way, if you want to make a point of 20%, the result should be 20%, not 16% or 23%. In addition to accurate level reproduction, the correct calibration of the imagesetter can also help you avoid the combination of highlights and dark parts. For the film output by the Imagesetter, the exposed part is black, and the unexposed part is transparent. There is no change. The word "density" is used to measure the blackness of the exposed part. It is the result of a logarithmic operation. The larger the value, the greater the blackness. The maximum density of a medium is Dmax. To measure the opacity or blackness of the substrate, a special densimeter is needed. There are two basic types of densitometer. Transmission densitometer is used to measure the density of film, and reflection densitometer is used to measure the density of printed matter. Of course, there are densitometers with both functions. The densitometer should be calibrated before each calibration of the control row machine. The density of the output film mainly depends on the setting of the exposure value of the imagesetter. Most imagesetters can control the intensity of the laser beam. The greater the laser intensity, that is, the greater the exposure value, the darker the output image, that is, the greater the density. In order to get high-quality output, we must choose the appropriate exposure intensity, which can not only express the pure black text with sufficient density, but also accurately express the gradient image. This process is not simple, because the imagesetter cannot directly represent continuous tone images, and can only be simulated by halftone addition. The exposure intensity used to generate real black text (usually its logarithm density value is between 3.5 and 5.0) is likely to be too heavy for the reproduction of photo images. If the maximum density is too high, some details will be lost. Text documents will lose serifs and gray ladders will be biased. If the maximum density is low and the developed film is not dark enough, it will not meet the requirements of printing. You can first adjust the exposure to meet the density requirements of pure text documents, and then use the calibration software of the imagesetter to generate the postscript transfer function (look-up table), so that the 5-gold cover often used by the imagesetter is not enough to meet the gray value specified in the front-end typesetting design software such as QuarkXPress, CorelDRAW and Adobe Photoshop. But there are also many factors that will affect the final output, including: process parameters (liquid concentration, temperature and tablet making speed); Film type and batch; Point parameters and imagesetter accuracy; It is very important to ensure the stability of the punching process and make the punching machine reach the standard working group parameter state before calibrating the imagesetter. The fluctuation of reagent concentration, oxidation rate or flushing time will affect the output quality. The following conditions will increase the density of the output: increase the developer concentration; Reducing the washing time and maintaining the stability of the punching environment at a higher temperature is a very critical step, which requires regular maintenance of the punching machine. After each addition or replacement of new liquid medicine, it should be recalibrated against the platoon machine. The best exposure intensity of the imagesetter depends on the type of film. Some photosensitive emulsions are more sensitive to the trick of pouring laser very quickly, which makes it easier to overexpose. Film thickness is also a factor to consider. To get the best exposure value setting, corresponding detection can be carried out to generate the transfer function of the Imagesetter, so as to ensure the accurate point size. The performance of different batches of film is also different. Ensure that only the same batch of film is used every time, and calibrate the imagesetter for this batch of film before using a new batch of film

halftone points are jointly determined by the accuracy of the imagesetter and the number of lines added

the resolution of the imagesetter reflects how much the arrangement density of the function controls the exposure of the laser beam on the film to form exposure points. Each exposure point is formed by focusing a laser beam on the film. The exposed area will turn black during development. The denser the exposure points are arranged, the higher the resolution is, and the greater the maximum density can be obtained. If you have calibrated the densitometer and found the appropriate exposure intensity, then it is time to generate the transfer function. The transfer function is actually a look-up table, which can be used by the imagesetter to ensure that the output point area ratio is consistent with that specified in the front-end typesetting software. This process is often called linearization. For each film type, resolution, number of lines added and point shape, we are further strengthening the combination of material research and development, and we should create a transfer function for it separately. The prepress toolbox, the imagesetter application of prepress solution company, is a typical transfer function generation tool. First, the uncalibrated imagesetter outputs the test sample of the gray ladder containing the typical point percentage, then measures the gray ladder with a densimeter, and then inputs the measured actual output point percentage into a dialog box, and then the preview toolbox can automatically generate a PS transfer function, so that the imagesetter can compensate the received gray ladder point area rate data before exposing the film, The data that actually controls the exposure is the data after compensation. Finally, use the newly generated transfer function to output the test sample to see whether it meets the required accuracy. If not, a new and more accurate transfer function should be generated based on this transfer function. During actual production, such tests should be repeated every other period to ensure the stability of production quality. The prepress toolbox and Panther Rip can store multiple transfer functions, which correspond to the combination of different types of film, resolution, number of lines and shapes. Of course, similar products from other manufacturers may also have this function. Calibrate your imagesetter regularly and pay close attention to various possible influencing factors. Your production quality will be more stable

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