Page 1:The Two Reasons To Calibrate Your Monitor
Page 2:Levels: The Key To Contrast And Detail
Page 3:Gamma: The Key To Maximum Image Depth
Page 4:Grayscale: Why White Is The Color Of Everything
Page 5:Gamut: What Color Is Your Monitor?
Page 6:Application: How To Adjust Levels
Page 7:Application: How To Adjust Gamma
Page 8:Application: How To Adjust Color Temperature
Page 9:Application: How To Adjust Color
Page 10:Calibrate Your Monitor For A Better Picture
Gamut: What Color Is Your Monitor?
If you read the explanations of color gamut in our monitor reviews, or in Display Calibration 101: Step-By-Step With Datacolor's Spyder4Elite, then you know that color gamut is another standard by which displays are matched to each other, as well as to cameras and printers. While it is possible to have a screen with a built-in color management system, it’s far more common to create a look-up table, called an ICC profile, that reconciles differences between a monitor’s actual color gamut and the target values.
Below we have a different representation of the CIE chart.
We chose this one because it shows the two gamuts currently available on computer monitors: Adobe RGB 1998 and sRGB. As you can see in the graphics, they are subsets of the full chart, which portrays the spectrum of color visible to the human eye. How close a display comes to these gamuts is a very important part of our testing.
There are other standards besides these two. The most common one is Rec. 709, which is used by high-definition televisions and projectors. Why don’t we show it on the chart? Because it’s identical to sRGB. They are indeed interchangeable. The other standard we’ll mention briefly is Rec. 2020, which is still a proposed spec and not currently in use on any production displays.
This is the proposed color gamut for ultra-high definition screens at both 4K and 8K resolutions. When this gamut is actually used in a monitor, you’ll need appropriate content to match it. And that is unlikely to happen without major upgrades in optical disc storage capacity and bandwidth, since it requires a minimum of 30 bits per pixel to encode.
How does this apply to our discussion? All fixed-pixel displays use three primary colors, red, green, and blue, to display an image. In the case of an eight-bit panel, 2563 gives us a possible 16,777,216 colors. Obviously, the positions of those primaries on the CIE chart are of paramount importance. Assuming that the camera used conforms to the standard, the only way we’ll see the same image is if our monitor conforms to the same standard.
That’s simple enough to understand, but what about the secondary colors?
In between the primary color points are the secondary ones: cyan, magenta, yellow. These are created by mixing two of the primaries in a particular ratio. The technical term is phasing and it’s important that a display does this correctly. A screen can have spot-on primaries, however, if the secondaries are off, visible color errors will result. Previously, we saw that adjusting the white point can help align secondaries. And most of the time, this is the only thing we can do to improve a display’s color accuracy.
Now we’ll get into some actual application of all this science. We’re going to explain just how we calibrate a monitor using its built-in controls only. This is exactly what we do for our reviews.
- The Two Reasons To Calibrate Your Monitor
- Levels: The Key To Contrast And Detail
- Gamma: The Key To Maximum Image Depth
- Grayscale: Why White Is The Color Of Everything
- Gamut: What Color Is Your Monitor?
- Application: How To Adjust Levels
- Application: How To Adjust Gamma
- Application: How To Adjust Color Temperature
- Application: How To Adjust Color
- Calibrate Your Monitor For A Better Picture