In daily life, we can also feel that when viewing the same object under different light sources or environments, the color of the items presented in our eyes will be more or less biased, because different light sources have different spectral characteristics , When illuminating the same object, different colors will appear. A similar situation will also occur when performing color management in a printing house. For example, although the quality inspector has carefully compared the color of the product, when the product is delivered to the customer, the customer will also receive a complaint from the customer about the color difference of the product. It may lead to the return of goods or customer claims, and the company ’s reputation will naturally be affected. To effectively solve this problem, the easiest way is to verify the color of the product under the same light source and controllable conditions, such as the commonly used fluorescent lamp CIED65 (that is, 6500K color temperature), otherwise all evaluations are meaningless. To achieve this, it is better to use the most commonly used standard dichroic light source. As a customer service staff that provides quality testing instrument manufacturers for printing factories, I contact the quality inspection department of printing factories all the year round. The following discusses how to carry out standard color matching and the requirements of the following conditions. Light source standard 1. Use fluorescent lamp D65 The fine color discrimination work in industrial production requires that the lighting source has a true daylight spectral distribution (including ultraviolet radiation and spectral radiation), and the fluorescent lamp D65 recognized by the International Commission on Illumination (CIE) can perfectly imitate real daylight. 2. Light source characteristics The illuminance of the light source ranges from 750 to 3200 lux (Lux), the color rendering index is> 90, and the uniformity is> 80%. 3. Requirements for background color Obvious colors are a subjective feeling, so comparing colors against different backgrounds can produce different results. Therefore, all background colors are defined as Neutral Grey with a Munsell brightness value of 6-8. 4. Requirements for environmental factors during color discrimination Try to block all external light that may hit the detector. If the window is in the field of view, gray curtains should also be installed, so it is ideal to distinguish colors in a dark room. 5. Record the usage time of standard lamps All standard light sources are served by lamps, and lamp manufacturers will also list their products to operate within a certain amount of time, so an accurate time recorder is required. Usually these lamps have to be replaced after being used for some time. 6. Arrangement position of lamps There is no specific requirement for the arrangement position of the light tubes, but the arrangement position must have a uniform light source in the light box, and must not be sideways to a certain area. The correct use of standard light source 1. Observation angle The above are the necessary facilities for standard light sources, but the viewing angle will also directly affect the color discrimination results. According to international standards, only two viewing angles can be used: a. 0 ° light source, 45 ° observation (0 ° / 45 °), that is, the light source is irradiated on the printed matter at a 0 ° incident angle (vertical), and the observer observes the printed matter at a 45 ° angle. b. 45 ° light source, 0 ° observation (45 ° / 0 °) using a specific 45 ° inclined table (45 ° Fixed Angle Table), the light source is irradiated on the printed matter at a 45 ° angle, and the observer is at 0 ° observation angle (vertical ) Observe the print. 2. Placement of printed matter Regardless of which observation method is used, prints should be placed in the middle of the light source as much as possible to reduce the influence of external light sources. The most important thing is that when you need to compare the colors of two or more items, try not to overlap them and watch them, preferably placed side by side under the light source. Alumimium Press Non-Stick Fry Pan Wok Pan,Non-Stick Saute Pan,Non-Stick Multifunction Wok,Aluminium Press Non-Stick Wok Pan HOMEARTS INDUSTRIAL CO.,LTD , http://www.kitchenworks.cc
Methods for printing companies to distinguish colors