With a significant improvement of optical technology, 4K applications have become more and more popular. The 4K video has become synonymous with "high-definition."

The 4K LCD monitors are the most common 4K devices. Both professional video producers, as well as consumers, use 4K monitors.    However, there are many different types of 4K LCD monitors on the market. Many of us may ask why some 4K monitors offer a horizontal resolution of 4096 pixels, and some offer 3840 pixels? And what are the differences between "Real" 4K and "Fake" 4K monitors? In this article, we will answer all those questions.

Knowing the difference between 4K and UHD

4K UHD is the most common abbreviation for the 4K applications. But initially, 4K and UHD are two different standards developed for various industries. The term "4K" originally derives from the Digital Cinema Initiatives (DCI), a consortium of motion picture studios that has developed a standard for 4K video content, applying 4096 x 2160 pixels as the resolution standard.

UHD stands for Ultra High Definition, a standard for broadcast and consumer display. UHD is four times the resolution of Full HD. In other words, compared to the Full HD resolution, which is 1920 x 1080 pixels, UHD features a resolution of 3840 x 2160 pixels.

The 4K in cinema standard (4096 x 2160 pixels) and the UHD in consumer display standard (3840 x 2160 pixels) are different in horizontal lines. The aspect ratio of videos for TV broadcasting is 16:9; however, the standard aspect ratio is 1.85:1, equivalent to 4096 x 2160 pixels in the cinema industry. Although the overall pixels of 4096 x 2160pixel and 3840 x 2160pixel are slightly different, the horizontal pixels are both close to 4000 pixels. Thus, 4096 x 2160pixel and 3840 x 2160pixel are generally referred to as "4K Standard ". Additionally, the 4K standard is more commonly known as 4K UHD to emphasize the difference between 4K and Full HD.

What is the Difference Between RGB 4K and RGBW 4K?

Another dispute over the 4K resolution is about the RGB and RGBW panels applied in the LCD monitors.

The RGB color space is a common technique applied in the panel. The RGBW technology is another technique that uses four sub-pixels comprising red, green, blue, and white in the panel. In an RGB panel, each column has 3840 pixels, and each pixel consists of three independent sub-pixels – red (R), green (G), and blue (B), so there are 11520 sub-pixels (3840x3) in each column. The RGBW panel comprises four sub-pixels: red, green, blue, and white (W). Each pixel is made up of four sub-pixels: red, green, blue, and white. And for every pixel, there are only three-color pixels, thus resulting in 3840 x 3 x ¾ = 8640 color sub-pixels in an RGBW panel. The total numbers of sub-pixels are only 75% of the RGB panel. The competition among the panel manufacturers is very intensive, some RGB panel manufacturers would like to advertise their RGB panels as superior to the competitors' RGBW panels, so call the RGB panel is the "Real 4K" panel which compares to the RGBW panel as "Fake 4K panel".

Because the RGBW panel has the white color sub-pixel, the white-color light results in the image's color saturation not being as high as the RGB panel. However, the RGBW panel also has features that the RGB panel doesn't have. The white-color sub-pixels of the RGBW panel provide better transmittance, yielding a better color transparent image. Also, as the panel's light transparency improves, the RGBW panel can achieve the same brightness as the RGB panel by using fewer backlight modules. As a result, the RGBW panel consumes less power, and the manufacturing cost of the RGBW panel is also lower than that of RGB panels. 

A summary of the pros and cons of RGB panels versus RGBW panels is given in the table below.

Summary

The optical technology keeps on improving, and the 4K displays are not the final milestone for the optical industry. The new 8K applications have been on the way. The technical roadmap of the optical industry goes toward higher resolution. The digital resolution will sooner or later go beyond the limit of human eyes. Here we suggest that consumers do not fall into the "Real 4K" or the "Fake 4K" myth when choosing a 4K monitor. Resolution should not be the only determining factor for purchasing a monitor. More essential elements such as screen size, color presentation, viewing experience, price, warranty etc. should be considered before making the purchasing decision.