DisplayCAL's complete guide to calibrating photography and design monitors

Calibrate a monitor with DisplayCAL It has become almost a mandatory ritual for anyone who edits photos, designs, or works with video seriously. Although many colorimeters come with their own software, more and more people are abandoning it and switching to this free solution because it allows them to get the most out of the hardware and truly understand what the screen is doing with color.

If you've ever calibrated using Datacolor Spyder software or X-Rite's basic utilities and then tried DisplayCAL, you'll know that the difference in control, information, and precision It's huge. It's not magic: it combines a relatively user-friendly interface with the ArgyllCMS color management engine, one of the most comprehensive available, and that's why it has gained fame even above many paid commercial tools.

What is DisplayCAL and why is it so popular among photographers and designers?

DisplayCAL is a Free software application for calibrating and profiling screens (monitors, projectors, and even some televisions) that runs on Windows, macOS, and GNU/Linux. Formerly known as DispcalGUI, it is currently distributed under the GNU GPL v3 license, meaning its code is open source and can be audited and improved by the community.

The program acts as a user-friendly graphical layer on top of ArgyllCMSArgyllCMS, the color management engine developed by Graeme W. Gill, is extremely powerful, but managing it from the command line isn't exactly convenient. DisplayCAL, created and maintained by Florian Höch, puts that power within anyone's reach with a tabbed interface, wizards, and detailed checks.

A key point is that You are not dependent on the software that comes with the colorimeter manufacturer.Many official programs are very limited: almost entirely automatic workflows, few advanced options, and worst of all, they barely show any useful data about the result (no complete reports on Delta E, color space coverage, true gamma, etc.). With DisplayCAL, you can use that same hardware, but with much finer control.

Furthermore, it has become the A great alternative for GNU/Linux usersColorimeter manufacturers typically release software only for Windows and macOS, neglecting Linux. DisplayCAL, thanks to its use of ArgyllCMS (available in repositories across many distributions), fills this gap and allows for consistent calibration quality on any operating system.

Compatible measuring devices and probe recommendations

One of the great advantages of DisplayCAL is that Any instrument compatible with ArgyllCMS is usable in DisplayCALThis includes the vast majority of colorimeters and spectrophotometers that have come onto the market in recent years. In practice, we're talking about more than twenty colorimeters and several spectrophotometers, with an official list available on the project website.

Among the supported colorimeters we find well-known models such as X-Rite i1Display Pro, ColorMunki Display, Datacolor Spyder (4, 5, X)i1 Display Studio, etc. It is also capable of working with i1 Pro spectrophotometers and other professional devices, although the latter are usually geared towards high-level studies due to price and complexity.

In practice, it is worth noting that Not all colorimeters are equally accurate or consistent.For example, Spyder5s are known for their variability between units: you buy two and they measure differently, making them unreliable tools for critical work. Many users end up describing them as little more than "expensive paperweights."

For value for money, a ColorMunki Display or an X-Rite i1Display ProThe first is slightly slower, but perfectly adequate for demanding photography and design work. The i1Display Pro is faster and somewhat more precise, and allows for more advanced workflows (including internal hardware calibration on some high-end monitors); if you also need to choose a display, see choosing the best studio monitor.

It must be remembered that a spectrophotometer (The i1 Pro 2, for example) offers more versatility, being able to calibrate printers and other devices, but the cost skyrockets, and for most desktop photographers and designers, a good colorimeter is sufficient.

Installing DisplayCAL and ArgyllCMS on GNU/Linux and other systems

In GNU/Linux, DisplayCAL and ArgyllCMS are usually available in the official repositories of distributions such as Debian, Ubuntu, Linux Mint or openSUSEIn these cases, simply install the corresponding packages, which are usually called “argyll” (or “argyllcms”) and “displaycal”. In some older versions of Ubuntu, it still appears under the previous name “dispcalgui”.

If your distribution doesn't include it in its repositories, or you prefer updated versions, You can download .deb and .rpm packages from the official DisplayCAL website.On Windows and macOS, the installer is classic: you run the file, accept the installation, and the first time you open the program, it will offer to automatically download and install the ArgyllCMS libraries necessary to function.

On the first startup, DisplayCAL will ask you Confirm ArgyllCMS downloadAccept, wait for the process to complete, and from then on you'll have the measurement and profiling engine up and running. On Windows, the firewall may ask if you want to allow access; it's best to grant permission for everything to work smoothly.

It is also important to monitor the driver conflicts with manufacturer's softwareFor example, if you're using an X-Rite, it's not a good idea to have the official app running in the background while calibrating with DisplayCAL, because both will try to communicate with the same device. Simply close the official utility from the Task Manager before starting.

Calibration and profiling: what they mean and why they matter

When we talk about “calibrating a monitor” in the real world, we almost always mean Two different processes: calibration and profilingIn the DisplayCAL documentation, "calibrate" is also used as a generic term to encompass both steps, although some specialists prefer to speak of "adjusting the monitor" to refer to the whole.

the phase of calibration This involves modifying the physical behavior of the screen to meet certain objectives: white level (brightness), white point (color temperature), black level (depth), and tonal curve (gamma). These corrections are made by adjusting the monitor's controls (brightness, contrast, RGB levels) and the graphics card's output until we get as close as possible to the established targets.

the phase of profiling It comes next. Once the screen behaves more or less stably and in line with those objectives, a more extensive measurement is launched with hundreds or thousands of color patches. With that data, the software generates a ICC profile that describes the actual screen response: what range of colors it can display, how each tone responds, how shadows and lights behave, etc.

This ICC profile is loaded into the operating system and into color management programs (Photoshop, Lightroom, Capture One, etc.), which use it to Translate correctly between working spaces (sRGB, Adobe RGB, DCI-P3…) and the physical deviceWithout a profile, the system assumes the monitor is ideal, leading to deviations that can be enormous on uncalibrated monitors. You can check how Import and export color profiles on Windows if you work on that system.

Therefore, although we colloquially talk about "calibrating the screen", what we are really looking for is calibrate + profileThe better you do in the calibration phase (making the most of the monitor's physical options), the finer and less forced the ICC profile will have to be, and the lower the risk of banding or artifacts from overly aggressive corrections in the graphics card's LUT.

Key concepts for understanding calibration with DisplayCAL

To get the most out of DisplayCAL, it's helpful to understand four or five basic concepts: white point, white level, gamma, profile and Delta EThese are terms you'll see over and over again in the program and reports.

El White Point This is the color temperature at which we calibrate the monitor's white point. It's common to use something close to 6500 K, which represents neutral daylight. In practice, color spaces like sRGB use a white point called D65, which is precisely defined as the intersection between the 6504 K isotherm and the daylight spectral curve. Whether it's 6500 K or 6504 K is practically irrelevant: the errors of the instrument and the monitor itself are much greater than such a minor detail.

DisplayCAL allows you to define the target in several ways: such as correlated temperature (6500 K), as “D65 daylight” white, or by directly entering the xy coordinates of the CIE spaceIn everyday use, for photography and web design, using D65 or 6500 K daylight is the most convenient and consistent with sRGB and Adobe RGB.

El white level This is the luminance or brightness setting you want to work with, measured in cd/m². You can leave it on "Native" if the monitor's current brightness is comfortable for you, or set a specific value (for example, 120 cd/m² for a moderately dark room, slightly higher if you work in a brightly lit office). The idea is for the screen brightness to match the ambient lighting, so that photos don't appear too dull or excessively bright when viewed in print or on other devices. If you work with HDR in Windows, you might also be interested in how to... calibrate the maximum brightness with Windows HDR.

La gamma This is the curve that describes how the monitor transitions from black to white. On most desktop computers, a gamma of 2.2 is the de facto standard and usually matches the factory settings quite well. If you choose other specific curves (for example, BT.1886 for video), you should ensure that it corresponds to the actual use of the monitor, but for photography and general design, 2.2 is the most sensible choice.

El profile type Another relevant parameter is DisplayCAL, which allows you to create profiles such as "Curves + Matrix," "3D LUTs," etc. For most monitors and photography and design applications, the "Curves + Matrix" mode offers a good balance between accuracy and performance. 3D LUTs are more resource-intensive and are intended for very demanding workflows, professional video, or when the monitor is known to have highly complex behavior.

Finally, the Delta E Delta E is the numerical measure of color difference between the ideal and what the monitor displays. DisplayCAL reports show average and maximum values; the lower the value, the better. An average Delta E below 1 and a maximum below 3 are generally considered excellent for photography and demanding design work.

DisplayCAL step by step: from installation to profile verification

Once DisplayCAL and the ArgyllCMS libraries are installed, the first stop is the Main screen, where the active screen and the instrument are displayed connected. In “Display” you will see the monitor you are going to calibrate; in “Instrument/Port”, the detected colorimeter or spectrophotometer.

If you are using a Datacolor Spyder, it may be necessary Activate the specific support from the menu Tools → Instrument → Activate Spyder colorimeterX-Rite devices are usually recognized without any additional steps, provided there is no other software interfering. If something goes wrong, a common workaround is to unplug and plug the probe back in and tap the reload icon (circle of arrows) in the "Instrument" section.

Before you jump in, it's a good idea to check some advanced settings, such as the “Unattended calibration” For certain X-Rite models, this allows you to skip the instrument's interactive self-calibration, making the entire patch-reading process completely automatic. It's also a good idea to adjust the system's power settings so the display doesn't turn off or go into sleep mode during measurement.

In the general settings tab, you choose the observer (normally CIE 1931 2°)The white point, white level, gamma, calibration speed, and the type of ICC profile to generate are all factors to consider. For a standard photography/design workflow, a very reasonable combination would be: D65, 120 cd/m², gamma 2.2, medium shutter speed, and the "Curves + Matrix" profile.

Once that's done, it's time to attach the colorimeter. It's hung over the center of the screen, with its counterweight behind it, and adjusted so that the lens is completely adhered to the surface and within the box that displays DisplayCAL. Make sure that the Windows “night light” solution or system color filters are disabled, unless you want to make some very specific adjustment.

Pressing “Calibrate and profile…” will start DisplayCAL, initiating a brief instrument check phase, followed by a colorimeter pre-calibrationSome models require you to cover or open the lens at specific times; the program will guide you through the process. Then the "Interactive Monitor Adjustment" window appears.

This phase is crucial: you will see several bars that represent the deviation of the RGB channels and brightness from the targetsYour task will be to access the monitor's OSD menu and adjust the red, green, and blue gain controls, as well as the brightness, until the bars are as close as possible to the reference marks. The more precise you are here, the less the ICC profile will need to be corrected later.

If you use a laptop or monitor without RGB balance control, you will need to Do what you can with the brightness and assume that the white will be somewhat less adjustable.In extreme cases, some people use Windows' "Night Light" function to approximate the color temperature to D65, but this is not ideal; it is much better to work with a monitor that allows individual control of the three channels.

When you're reasonably close to the target on the bars, press "Stop Measurement" and then "Continue Calibration." From there, DisplayCAL will begin the lengthy patch reading process, which can take anywhere from 20–30 minutes to over an hour, depending on the number of patches chosen, probe speed, and LUT type that you are going to generate.

When finished, the program will display a window with the coverage and range of your monitor Regarding color spaces like sRGB, Adobe RGB, or DCI-P3, it's a very direct way to check if the panel lives up to the manufacturer's claims. From there, you can click "Show profile information" to view CIE charts, gamma curves, error distribution, etc., and finally install the resulting ICC profile on your system.

Creating 3D LUTs and using them with madVR and other video processors

In addition to classic ICC profiles, DisplayCAL can Generate 3D LUTs for videoThese are very useful if you work with madVR, Lumagen, eeColor, or other external processors. A 3D LUT is basically a table that indicates, for each combination of RGB input, how it should be transformed to obtain an output calibrated according to a specific color space and gamma (for example, Rec.709 + gamma 2.2 or Rec.1886).

The process starts the same way: DisplayCAL is installed, ArgyllCMS is downloaded, and the probe is connected. On the first tab, under “Settings,” you can start from a specific preset like “Video 3D LUT for madVR (D65, Rec.709/Rec.1886)”When you select it, you will see that the target screen changes to “madVR”, indicating that the output device will be the madTPG (madVR Test Pattern Generator).

In the “Profiling” tab, you can define the number of patches to measure. For a minimally serious 3D LUT, the following are recommended: thousands of patches (around 3.500)However, this significantly increases the measurement time. You can also add a suffix to the profile name or change the location where it will be saved. In the “3D LUT” tab, you choose the mesh format and resolution, and in “Verification,” you can prepare templates to check the accuracy later.

Before starting the measurement, it is advisable to leave the display device adjusted as best as possibleBrightness, contrast, white balance at 100% IRE, and deactivation of dynamic modes (dynamic contrast, auto iris on projectors, etc.). On projectors with very deep blacks, you may need to disable the iris or increase the lamp power so the probe can read the black level (the i1Display Pro requires a minimum of around 0,004-0,006 nits). If you work with HDR content on Windows, also remember Activate and calibrate HDR in Windows 11 according to your workflow.

When you press “Calibrate and profile”, DisplayCAL will launch madTPG, where you must maximize the window or put it in full screen and place the probe inside it. On projectors, it's sometimes advisable to use large test windows to avoid measurement problems, and it may be recommended to select the "Disable OSD" option in madTPG so that the menus don't interfere.

When finished, DisplayCAL will offer to install the LUT directly in madVR. Later, you can go to the calibration section of madVR and verify that The 3D LUT is correctly loadedPlayers like MPC-HC allow you to activate and deactivate the LUT or even slide between both states to quickly appreciate the difference between the calibrated image and the original.

Verification of results and advanced testing with DisplayCAL

Once you have calibrated and created the ICC profile, it is highly recommended to use the tab of "Verification" Use DisplayCAL to check how everything turned out. This section allows you to remeasure the monitor using specific patch charts and generate very detailed HTML reports.

You can choose from multiple types of report, such as “Profile Verification Adjustment Chart” and select a reference color space (e.g., DCI-P3 or sRGB). After a shorter measurement than calibration, the program generates an HTML document with average and maximum Delta E values, CIE charts, gamma deviation, white point, etc.

You also have additional tools available in the Tools → Report menu. From there you can perform screen uniformity testsThis test measures luminance and, in some cases, color at various points on the panel to see if there are significant differences between the center and the corners. It is very useful for detecting monitors with serious problems such as uneven brightness or dominant colors in certain areas.

Another interesting feature is the Quick screen report, uncalibrated or already calibratedIt shows you at a glance data such as the current color temperature, effective gamma, contrast, brightness, and an estimate of the monitor's color depth. This helps you set realistic goals before you begin (for example, knowing if your panel can actually reach a certain color space or a very low black level).

All these reports allow you to compare the “before and after” of the calibrationYou'll see in numbers and graphs how color errors have been reduced, whether the gamma is better adjusted to the desired level, whether the white has approached D65, and to what extent the sRGB, Adobe RGB, or DCI-P3 coverage corresponds to what is expected for that specific model.

Ultimately, the combination of a decent probe, DisplayCAL, and ArgyllCMS offers a level of control and transparency which is rarely achieved by manufacturers' basic software. It might require a little more time at first, but in return you'll have the peace of mind that the photos, videos, and designs you see on your screen are truly close to reality and will reproduce much more accurately on other devices and printed copies.

Related articles:

ICC Profiles in Windows 11: A Complete Installation and Usage Guide

Isaac

Passionate writer about the world of bytes and technology in general. I love sharing my knowledge through writing, and that's what I'll do on this blog, show you all the most interesting things about gadgets, software, hardware, tech trends, and more. My goal is to help you navigate the digital world in a simple and entertaining way.