Want vivid colors? Focus on the projector's color brightness (CLO) indicator

The projector used in the author's audio and video room has always been the Epson CH-TW5350 - this is a standard 3LCD model. And I am currently considering upgrading it to a more advanced 4K enhanced + HDR model, such as the Epson CH-TW8300. A friend may ask: Epson's projectors have long used 3LCD technology. Does this mean that you are more interested in 3LCD? The author's answer is yes.

In fact, there is also an ultra-short focal projector projection based on DLP technology in my living room. However, it is usually used only by my family leaders to chase dramas or to see daily news reports. If we go to see the newly arrived Blu-ray discs once we are ready, we will return to the audio and video studio to open the Epson 3LCD projector. The most important reason is that I think the Epson 3LCD projector's color performance is better than the average DLP!

Since my daily work is related to photography, I also attach great importance to the color performance of various types of imaging equipment. On weekdays, I will often use my camera's proofs to zoom in on the screen with my friends and relatives. Therefore, even some small images will affect my viewing experience. Currently, 3LCD projectors are better than other technologies in terms of their ability to restore fine levels or color convergence. For example, to represent large-area sky scenes, 3LCD can easily restore large, delicate and subtle shades of sky without annoying "color-grading faults"; for example, the color convergence that may occur compared to some projectors does not In addition, 3LCD technology will not allow strange color outlines on the edges of objects. In addition, 3LCD technology will not cause visual fatigue caused by rainbow eyes due to technical defects.

Of course, the most attractive place for Epson 3LCD projectors is its accurate reproduction of colors: the same photo, on the Epson 3LCD model, looks full of color, vivid, strong and distinctly three-dimensional. However, why does this picture look dull and deadly on other models? In the beginning, I always thought that this was because of the different brightness of the two projectors. However, comparing the parameters of the two tables, I found that the nominal brightness values ​​were almost identical. Why are they so different in actual color performance? In fact, this involves a Color Light Output problem.

We all know that an important parameter to choose a projector is to see how bright it is. Although various brands of projectors on the market have given a variety of different brightness test methods and indicators, the most common test method is to divide the projection screen into 9 areas of the same area, and then measure the brightness of the 9 area centers respectively. , and multiply the average value and the screen area to get the final brightness. It is noteworthy that this test method has been in use for many years, but it has a major drawback is that it only tested the brightness of the projection white light! If this kind of test method is more applicable to the digital reports (black letters on white) most often projected in the early years, it is in fact incomplete for the video content or high-precision color photos that we broadcast today.

Because of this, Epson pioneered the “Color Luminosity Output” (CLO) measurement method. In fact, this kind of test has similarities with the original white light brightness test, except that the original “only measure the white light brightness” is changed to “test the three primary colors of RGB (red, green and blue)”: through three consecutive nine-point measurements, the The average value of the RGB primary colors is multiplied by the screen area to obtain the final color brightness (CLO) value.

If the color brightness (CLO) of a projector is equal to the brightness of white light, then the color performance of this projector is very good. Otherwise, the color performance of the projector is not good. Take the CH-TW5330 projector used in my home as an example. Its white brightness and color brightness (CLO) are 2200 lumens, so this home theater projector has a very vivid color performance, not only can easily restore the movie Those fantastic and magnificent colors can also satisfy my need for displaying new camera evaluation samples. The CH-TW8300 series that I would like to upgrade in the future also achieved a white brightness and color brightness (CLO) of 2500 lumens. The higher color brightness combined with Epson’s 4K enhancement technology clearly makes the display of high-resolution photos even more perfect.

With regard to the color performance of the projector, I also specially asked my friend, Gao Gaosang. As a technical director of a professional audio and video equipment company, he is also very concerned about the color brightness (CLO) indicator of the projector. He told me that in fact, whether it is a projection or flat-panel TV, if you want to have good color performance, you must have a high brightness as a basis. This is actually why the new HDR TVs from several brands have recently been able to improve the color of LCD screens. For their company, as they often undertake the construction of conference room projection projects including high-end home theaters and enterprises and institutions, they have always been very concerned about the color performance of projection screens. In fact, there are many customers who are pointing directly at the computer screen to say to them that the projection of the future can achieve such an effect. Therefore, only one white light brightness does not guarantee the color performance of the final screen, and they are also willing to recommend models with higher color brightness (CLO) to the customer.

I sent a group of photos in WeChat. This is a professional AV audition room that they completed in Beijing late last year. It is also a coincidence that the location of this audio-visual room is very close to the headquarters of our Beijing company and is located near the Gaobeidian film and television creative base. The other party's client is also a film and video creation company. In the future, he intends to view the video demo in this video room.

The area of ​​this audio-visual room is quite large, and using a projection screen is 180-inch giant! The customer had originally prepared a DLP projector himself, but @Gao Gaosang reminded customers that although this DLP's projection size is enough to cover the entire screen, it is likely that the final screen looks dark due to insufficient color brightness, and the color performance is insufficient. . They specifically brought a higher-brightness Epson 3LCD projector to the scene to compare with the original DLP device. Upon starting up, the Epson projectors with higher color brightness (CLO) showed a clear color advantage, and the customers were quite satisfied with the brightness and color performance they exhibited, decisively agreeing to their host replacement program.

According to @Gao Gaosang, in fact, not only in home theater or film and television production, projectors with higher color brightness are also very useful in business, education, and engineering. At present, the color brightness measurement method has been incorporated into the IDMS "information display measurement standards", but also included in the "electronic projector measurement method" issued by the Ministry of Industry and Information Technology, as an important indicator to evaluate the performance of the projector. Therefore, for consumers, whether it is to buy a commercial projector or want to buy a suitable home projector for the home theater in the home, it is recommended that everyone should pay attention to the color brightness in addition to the brightness index (CLO ) indicators, so as to ensure that people see the color projection images of fresh people.