Hardware LUT Calibration for Dell Wide-Gamut Monitors

Reading Bill Peppas' recent article here on Fstoppers got me thinking about calibration again. For the most part, it's a fairly simple process to improve the accuracy of colors on your display. A good many of us simply need to invest in a Spyder or ColorMunki system and allow it to do its job. Correctly calibrating a monitor with a hardware Look-Up Table (LUT) is a little more involved, and I wanted to share the procedure for calibrating a Dell Monitor with the X-Rite i1 Display Pro.

Over the past few years, Dell has released a series of wide-gamut monitors (U2413/U2713H/U3014) with hardware LUTs that provide more affordable solutions to offerings from the likes of Eizo. Hardware LUTs offer greater colour accuracy, but require specialized calibration tools in order to make the most of them. In the case of Dell's monitors, this means using their software and an X-Rite i1 Display Pro (the only compatible tool). With this combination, calibration is able to be written into the monitor's LUT for the most accurate color reproduction possible.

I recently took advantage of a sale on the i1 Display Pro, as until recently, I had been calibrating using a regular Spyder 4 Pro for ICC profiling. I had known this was not as accurate as it could have been, but after having to deal with a recent camera failure, I wasn't ready to spend the extra money just yet. When the i1 Display Pro arrived, I eagerly took it out and began the process immediately. However, I ran into problem after problem with the calibration and so decided to put together this guide for calibrating these monitors on Windows.

Step 1: Preparing the OS

Before calibrating your monitor's hardware LUT, you will need to remove any existing software calibrations (ICC profiles) and calibration software. Calibration software can be removed using the Windows Add/Remove Programs dialog, and custom ICC profiles can be removed in the Color Management dialog. You will also want to check “Use Windows Display Calibration” in the advanced tab of Color Management. As Windows loads ICC profiles automatically into the graphics card on startup, you'll also need to restart your machine before proceeding.

The final step for preparing to use the Dell software for calibration is to disable User Account Control (UAC) in Windows. You'll need to be an administrator to do this. It can be found in the Users section of your control panel. In Windows 10, simply slide the selection down to 'never notify'. This will stop all of those messages that prompt you to give permission when you're installing new software. This is essential, as the Dell software will fail calibration if it is interrupted.

Step 2: Preparing the Monitor

As with all hardware, it is usually prudent to keep the associated software up to date. Be sure you have the latest drivers for the monitor installed. They can be found on Dell's website or through Windows Update. Also ensure that the upstream USB cable that came with the monitor is connected directly to a USB port on the computer. Do not connect this through a USB hub, as calibration may fail if you do.

The next step is to use the monitor's factory reset to bring it back to its basic settings. Using the monitor's menu, navigate to Menu, Other Settings, Factory Reset. As something you have set in the menu may affect the accuracy of the calibration, this is required before continuing.

Dell's monitors come with several factory default calibrations such as AdobeRGB and sRGB. These cannot be overwritten, so we will need to select a custom calibration to write to. Again, using the buttons on your monitor, select Menu, Color Settings, Preset Modes, Color Space, CAL1. You can also select CAL2 for a second calibration after your first is complete, allowing you to have, for example, an AdobeRGB calibration and an sRGB calibration. This may be useful for some applications such as web browsing, where AdobeRGB colour space can cause issues.

Step 3: Installing Dell's Software

The only application that can write the hardware LUTs required to accurately calibrate these monitors is Dell UltraSharp Calibration Solution. After running the installation, connect your i1 Display Pro to the USB port on the back of your monitor.

Step 4: Calibration

If you have completed all the steps above successfully, you should simply be able to have a cup of coffee while the i1 Display Pro does its job. So, put the kettle on and open the software.

The first screen you will see is Display Settings. If you have multiple monitors, select your Dell monitor here. From the drop-down lists, select your RGB primary. For me, I have set CAL1 to AdobeRGB for photo editing. You can allow the i1 Display Pro to measure the ambient light in your room and set the luminance accordingly, or you can choose a custom luminance. In my room, the i1 measured the appropriate luminance to be 100 cd/m^2. If you plan to set it manually, remember that between 80 and 120 cd/m2 is usually appropriate. Anything brighter and you may strain your eyes quite a bit.

The next screen will be Measurement. If everything has gone well, you will see your i1 Display Pro listed and a color swatch on the right-hand side of the screen. From the drop-down list, select the name of the calibration you are going to overwrite — in this case, CAL1 (calibration 1 in the software). Click "Start Measurement," place your i1 Display Pro as instructed, and get that cup of coffee.

Once it's all done, the LUT will be saved for you and an ICC Profile will be created for Windows to use. Save this, and enjoy the best your monitor has to offer.