Notes For Rolling Tipping Paper Screen Correction

^{Notes for Rolling Tipping Paper screen correction}

 

^{Definition of screen calibration}

^{In the past, many people have said that Calibration of the screen is to adjust the screen to what appears to be a print. It is usually done by using a printed copy as a benchmark and then using some software such as Adobe's Gamma or directly using the calibration function on the monitor. To achieve a color that is similar or identical to the print. However, this is an approach that did not previously have ICC workflows, which can only serve their own purposes, and may not show the same results for every software. There is no central control to unify the colors, so Apple developed a system extension program called ColorSYnc a few years ago. This is to use the ability of the system software to centrally process color, but the central controller needs some information about the color characteristics of different devices, which is called ICCprofiles, and to produce these ICCprofiles requires the appropriate hardware and software to be able to do it.}

 

^{Screen calibration is the first job}

^{Screen calibration we can be divided into two parts, the first is the control of the environment, because although the screen is a transmission type display, but the surface of the screen tube will also be affected by the light around the environment, such as when the light is directly exposed to the screen, the contrast of the image will be reduced in real time, the reason is that the tube glass reflects the indoor light, So that the part of the black position does not produce enough black. If the indoor light is turned off, the contrast on the screen is suddenly increased, but I believe that no one likes to work in the all-black environment, making workers feel uncomfortable. A better way is to properly control the lighting in the room, so that the light can not be directly exposed to the picture tube glass, a very effective method is to add a light block to the screen.}

 

^{Stable and standard lighting}

^{Just said that the indoor light properly control the contrast of the screen has good results, but many friends will ignore the lighting of the original manuscript, when we control the light can not illuminate the screen, the lighting on both sides of the screen is insufficient, and the color temperature is not allowed, so it is best to have a stable and standard reading light box. This light box is usually carefully designed, generally 5000K color temperature international standard, and the light reflection Angle does not cause reflection, and the lighting is average.}

 

^{Color temperature ClolrTemperature}

^{Color temperature is used to refer to the degree of its light hue white, to quantify the light color performance of the light source. According to scientific theory, a standard black body with full absorption and radiation capacity is heated, and the temperature gradually increases and the color changes. The temperature when the blackbody is heated to the near-light color corresponding to the light source is defined as the relevant color temperature of the light source, referred to as the color temperature, and the absolute temperature K (Kelvin, or Kelvin temperature) is the unit.}

 

^{The bluer the light color, the higher the color temperature; If the color is red, the lower the color temperature. The color of light during the day also changes with the time of day; 40 minutes after sunrise, the light color is yellow, the color temperature is 3000K; At noon, the sun is white, rising to 4800~5800K, and about 6500K at cloudy noon; Before sunset, the light turns red and the color temperature drops to about 2200K. In the artificial light source to divided tungsten bulb 2000~3400K, the general rice color light tube 2600~4000K, the general white light tube 6000~8000K, and we design the printing industry needs to have 5000K standard color light tube.}

 

^{Why have a standard color light! Because 5000K color temperature light source.}

^{(a) In the middle of the visible spectrum,}

^{(2) White light with color balance,}

^{(3) will not emphasize any color,}

^{(4) Internationally recognized standards.}

 

^{It is very difficult to reproduce all the colors on a computer screen, and it is well understood that it is virtually impossible to display an image on paper without deviation on a screen, because the colors on a screen and on paper are produced by completely different physical phenomena.}

 

^{Screen calibration and characterization}

^{It is very difficult to reproduce all the colors on a computer screen, and it is well understood that it is virtually impossible to display an image on paper without deviation on a screen, because the colors on a screen and on paper are produced by completely different physical phenomena. The color display of different brands of screens can be very different, and the temperature of the screen is another factor; After the same screen is opened for a few hours, the color displayed may be different, and the aging of the hardware also affects the stability of the color display; The phosphorus in the screen will decay over time. Finally, the external light sources of your work environment also come into play, as they mix with the colors emitted by the screen when projected on it.}

 

^{The color temperature of the unadjusted white dots on the screen is higher, and its color temperature is between 8000 and 9500K, which is obviously blue. In order to have a similar color effect between the screen and the manuscript or printed product, you should set your screen WhitePoint to the same color temperature as the indoor light bulb when you look at the color. And the purpose of setting the appropriate Gamma value is to adjust the contrast of the screen display to be consistent with the typing or printing. The working steps of screen calibration are as follows:}

 

^{(1) First fix the light at the working position, or have a standard color light box for color.}

 

^{(2) Start the heat engine on the screen for at least 30 minutes, so that the picture tube of the screen reaches a stable state.}

 

^{(3) Close the desktop pattern, and change the background of the screen to medium gray, so as to avoid the interference of the background color.}

 

^{(4) Start the screen calibration software.}

 

^{(5) Adjust the light and contrast of the screen with the software instructions, and use the tape to press the system or lock it with the software.}

 

^{(6) Select the white color temperature and contrast value, usually printing requirements WhitePoint is 5000K and Gamma is 1.8.}

 

^{(7) Hold the colorimeter or spectrophotometer in the specified position on the screen.}

 

^{(8) Then store the measured data and ICCProfile.}

 

^{Above is the general screen calibration steps, the following will explain the actual work of the situation, first use AppleClolrSync DefaultCalibrator, which is a free and easy screen calibration tool to help you calibrate the screen gamma value and white point. The method of use is very simple, just follow the instructions of the software, because single-eye observation to correct, the accuracy will be poor, if you want to have more accurate screen calibration, you may need some equipment, these devices include colorimeter, which measures the color of the light emitted by the screen through an instrument attached to the screen. The screen calibration software commands different colors on the screen. Colorimetric measures the color emitted by the screen, sends the data back to the computer, compares the actual color measured to the desired color that should be displayed, so that you can adjust the color temperature and gamma value Settings to get some kind of set goal.}

^{Finally, how to check whether the color and light and darkness of the screen display is moderate, teach you a simple method, open a blank window on the screen, and then put a piece of white paper under the color light source, and then use a card paper to open two holes, through the card paper to observe the color and light and darkness of the two holes, if the color temperature is not right, pull the software color temperature control to correct, if the light and darkness is not right, To change the intensity of the light source, it is necessary to have a dimmable light box that is easier to get the ideal effect. If you want a more accurate reading, you can use the focus meter that is easier to use photography to measure whether the white level on the screen and the white paper reading under the color light source are consistent, and the color temperature can be measured with the color temperature meter.}

 

^{Finally remind everybody, if equipped with special screen calibration program running on your system, then you are not to be used at the same time other calibration software such as AdobeGamma or AppleClolrSyncDefaultCalibrator.}

 

^{Once the screen has been calibrated, it is only necessary to recalibrate it if conditions change, or monthly recalibration is proposed if its luminescent "drift" changes. A good way to do this is to tape down your screen's brightness and contrast adjustment after calibration and keep the lighting conditions the same.}