Color Calibration is Essential for Creating Digital Imagery

What is Color Calibration?

During the editing and processing of digital images, the goal is to tailor imagery in order to communicate a specific intention. Color calibration is the process of fine-tuning a monitor in order to accurately display colors and shading, so as to synchronize what you see on your screen with what it will look like as a finished product. Calibration can be envisioned as the difference between using a tape measurer to judge length as opposed to just using your eye.

Why Color Calibration?

What’s the use in taking time to create great imagery if it’s not going to be seen that way? As your monitor is going to be your strongest ally during the digital editing process, it is important to ensure that the color output on your monitor is a precise replication of the finished product intended. When color output on your monitor is not calibrated correctly, inconsistencies in the color output of your monitor will arise. As a result, any effort put into tweaking and fine-tuning images will to go to loss, as the finished product will not come out consistent with the way it was designed when displayed on the monitor. This loss comes at the expense of valuable time and effort that could otherwise be put to use on other projects and can create a bottleneck in the workflow.

In fact, profession and enthusiasts photographers as well as graphic designers working from non-calibrated display monitors take up to three times as many print iterations to achieve an acceptable sample as those working from a calibrated display in a safe color viewing environment. In essence, working from a calibrated display serves as a means to boosting efficiency and reducing wasted resources such as time and costs, making the difference between guessing how a finished product will look and knowing how it will look.

Monitor Color Variation

Monitor color and luminance will change naturally over time for a multitude of reasons.

Displaying color in a linear way can create errors for matching while trying to find the correct shade values for each color. 3D LUTs are much better because they produce color using a volumetric color space, which is more accurate and reduces calibration errors. 3D LUTs are needed to help create better color graduation and help express the non-linear values that exist in real life. A wider color gamut and saturation are expressed while having the ability to better match shades of colors that create better color reproduction, especially during the editing process or when users manipulate chroma, hue and brightness. Converting one color space into another color environment is done better. When converting one color space to another, 3D LUTs are more precise, reducing lost color information from the original color gamut. Intermediate color gradation is improved due to the nonlinear behavior of 3D LUTs, enhancing gray scale accuracy.


Issues During Production
A Liquid Crystal Display (LCD) monitor is composed of three main components; a backlight, a matrix of LCD light valves, and a matrix of red, green, and blue filter elements. Naturally, these three components are subject to a wide range of variations for reasons such as batch-to-batch variation of materials and manufacturing tolerances that affect optical properties. Due to the nature of LCD monitor panels, it is especially common for most monitors to face issues related to these inconsistencies during production when not first receiving a pre-calibration from the factory. Monitors such as the Viewsonic VP2468, which come pre-calibrated with an individual color calibration report included from the factory, act as a solution to these issues to ensure color accuracy from the start.

Issues Over Long Term Usage
There are also material properties that can change with regular usage over time stemming from exposure to heat, humidity, ultra-violet (UV) radiation, etc. The variations can be seen to have an effect on backlight and color output quality, LCD polarization/light transmission efficiency, and fading filter spectral transmittance. These issues, however, can be counteracted by the means of calibration via software and hardware calibration.

Software Calibration and Hardware Calibration
There are two types of calibration methods for setting a monitor to a well-defined state; one being software calibration and the other being hardware calibration. These two types of calibrations range in the amount of precision and flexibility they deliver.

Software Color Calibration

Software calibration is conducted by first selecting a gamma to use, which will allow for a maximum range of colors your system can display. The next step involves setting black (brightness) and white (color) levels to their optimum values. A set of color patches will then be measured to determine the limits of the monitor’s display capabilities to generate an internal ICC color profile, which is a profile set in accordance with the standards put in place by the International Color Consortium. The ICC profile is then used by the operating system to perform color management and can be used as a method for ongoing color management. As this type of calibration is conducted by the user, drawbacks resulting from software calibration are that it can be both difficult and time consuming and include issues relating to precision, as a result. The most notable drawbacks can occur with regards to gradation characteristics stemming from the use of a monitor’s color-adjustment function and video-card output. Gradation deviations such as tinting and other damages can occur, which impact the monitor’s ability to display minor color differences and affect overall gradation display. These deviations can be even more drastic when working from a monitor with no color-adjustment function. Hardware Color Calibration Hardware calibration is also conducted by selecting a gamma to use and setting brightness and contrast levels. With hardware calibration, a specialized hardware calibration sensor is used to determine the limits of a monitor’s display capabilities captured at monitor level. Sensors can come as part of a kit, as is the case with the Viewsonic Colorbration kit, which comes included with the CS-XRi1 color sensor that has been co-developed with X-Rite, pictured below.

As the types of profiles created with hardware calibration are independent of the graphics card, this method allows for access to the profile anytime regardless of the host computer. Since hardware calibration controls the monitor directly, this type of calibration offers good gradation characteristics with high precision. There are a range of different controls that can be controlled with high precision depending on the type of digital image creation required. Accessibility to the hardware look-up table (LUT) allows for a more customizable color mode to fine tune colors and make further adjustments. Precise control of the monitor’s gamut is available with the ability to simulate Adobe RGB or sRGB with very high accuracy. Black level can be controlled with precision and is of major importance during the soft proofing process. Precise calibration through the full luminance range of the display without the loss of digital resolution is another benefit of this method.

Conclusion

As a long term and professional calibration solution, the benefits of hardware calibration greatly outweigh the benefits achieved by software calibration. A notable benefit of the functionality of hardware calibration allows for alignment of the graphics card and monitor scalar for a long-term consistency and accuracy of color output, which the more limited software calibration method is not able to provide. For those working with high quality imagery or within a professional design environment, hardware calibration serves as an excellent resource for a more efficient workflow and consistent quality of work.

 

All the images or videos within the product screens herein are simulated for demonstration purposes only; they may not be the actual images or videos displayed in the products screens.