Monitor Calibration

Introduction

If we isolate one of our clients products in 90% of the cases it can be split in two components: Shape or Model and Color. Both of these components are usually of equal weight and importance for our clients. Even though, apart from print where detail really matters, our work can be aimed at other media types like web and TV, it is as important to get these two main components as close as possible to reality. In these series of articles we will be focusing on getting the colors right and one of the first and quite fundamental steps in this process is Monitor Calibration.

Monitor Preparation

Monitor preparation consists of a few easy, straightforward steps which, however, are quite important and will help with better calibration quality.

1. Clean the screen - use a screen cleaning solution and a microfiber cloth to wipe all residue and dust particles of the screen.

2. Let the screen warm up/run for 30 minutes prior to calibration.

3. Make sure no direct light hits the monitor screen. If there are any artificial light sources in the room that directly affect the screen, make sure to turn them off.

Monitor Settings

The final step of the preparation is to reset all monitor settings to their defaults. However, this is not enough as some additional settings need to be applied for different monitor types. Two sets of settings need to be addressed:

01. Brightness and Contrast

Brightness and Contrast should stay with the default values. For Dell monitors that we use in Visual Method these would either be 50, 50 or 75,75.

If you don't want to reset the monitor settings, you can set these up manually if you know what their default values are for the specific monitor.

02. Preset Mode

The Preset Mode adjustment can be reached either through the menu or directly through the Preset Mode button on the screen. There are two options depending on the monitor type.

• Custom Color (Custom RGB) Preset Mode - this mode is used on 90% of displays. To set it up correctly for calibration select it from the menu, then select Gain as the type and set the R, G and B sliders to 80 (default is 100).

• Color Temp. Preset Mode - this mode is used on monitors that support Uniformity Compensation. Currently, the only available models with this are UP2516d and UP2716d. To set this up correctly select it from the menu and then select 6500k as the temperature (this is the default). After this is set up, make sure Uniformity Compensation (found under Display Settings) is set to Calibrated.

Calibration Software

The software that will be used for monitor calibration is called DisplayCAL. This is a 3rd party software that achieves considerably better results compared to software produced by the hardware manufacturers. If it is not already installed, latest version should be downloaded from here: https://displaycal.net/#download 

Installation

First, uninstall any other calibration software. This might be either the i1 Profiler from X-Rite ot the Spyder software from Datacolor.

Installation is pretty straight forward, just use the default settings. When running the software for the first time it will ask to download and install Argyll CMS. This is the color engine that is used to run DisplayCAL so this installation is mandatory. If there isn't any pop-up than most likely Argyll is already installed.

When the installation is complete you need to plug the Colorimeter (the calibration device) into one of the USB ports of either the computer or monitor. 

Display & Instrument Tab

The first tab of the software should appear like in the image above.

1. If that's not the case, it's because the Colorimeter device hasn't been detected. You can unplug and plug it back in or change the USB port (sometimes it has issues with monitor based USB ports) and hit the Refresh button. If it's still not detected than you might want to update USB drivers.

2. Select the monitor which you want to calibrate.

3. Set the Mode to LCD (generic). Refresh Mode is for CRT or Plasma screens.

4. Choose a correction type. This is based on the backlight technology used for the particular screen. To check the backlight type of the screen, go to: https://www.displayspecifications.com/  and write down the monitor model. From the image above as an example, it would be Dell UP2716D. Scroll down to the Backlight info to figure out the type of correction you need to use.

Within VM we currently have three types of Dell monitors. New wide Gamut monitors like the one above (these models usually start with UP), old wide Gamut monitors and quite a few normal Gamut monitors. These all use different backlighting technology so if you're unsure which one is the correct, double check with the website. A small list to start:

• Dell UP2516D/UP2716D - LCD GB-r_LED/RG Phosphor LED family

• Dell U2410 (old wide gamut) - LCD CCFL Wide Gamut family

• All normal gamut monitors are White LED or WLED - LCD White LED family

Calibration Tab

The Calibration tab is where we set the visual color representation that we are aiming to achieve.

1. Set the Whitepoint to Color temperature and 6500K.

2. Set the White level to Custom and 120cd/m². (For laptops leave this setting to As Measured)

3. The Calibration speed is the factor which will dictate how accurate the calibration is. Set to Low for best results if the time allows it. Medium is a good compromise. High is for extreme "better than nothing" cases. Very High is unusable, so don't calibrate with this setting.

Profiling Tab

The Profiling tab we use to set the name of the ICC profile that will be created for the current display.

1. The naming convention should be WorkstationName_MAIN/LEFT/RIGHT_Date. The software provides some placeholders to help: %nn will give the PC Name. %y%m%d (all small letters) will give back the date without the century. The only thing that needs to be manually written down is which monitor is this. For dual monitors systems we use LEFT or RIGHT. When calibrating two monitors, don't forget to change this name before starting the calibration of the second monitor. For laptops or single monitor setups, use the MAIN naming convention. Finally, an example would be VMWORKSTATION01_LEFT_200115.

2. Hit the Calibrate & profile button to start the calibration process.

Calibration Process

Once you hit the button the Measurement Area window will appear in the center of the targeted monitor. Place the Colorimeter in the middle of the window and make sure it's lying flat on the screen surface. If needed, you can tilt the monitor upwards slightly to create less of a vertical surface for the device to stay.

Once this is all set up press the Start measurement button. The software will do some pre-calculations and will then give the option for Interactive Display Adjusment. This is mainly to set the correct Brightness of the monitor but if the monitor has RGB Sliders, to also get as close as possible to the desired color representation. If the monitors hardware settings are correct for calibration (as per the guide above) press again the Start measurement button.

After a few tests DisplayCAL will show the current deviation from the desired RGB values and Brightness level and it's now time to adjust these settings on the monitor to match as close as possible. For monitors that have hardware Uniformity Compensation setting enabled, only Brightness needs to be adjusted!

For these it's easier to start with getting the RGB values correct first and then setup the Brightness (as it will be influenced by the RGB sliders). When optimal values are reached they will be indicated with green. Once you're done you can click Stop measurement and then Continue on to calibration. The process from here on is automatic.

Once the calibration process is complete a pop-up window will appear. Make sure to install the profile as system default so it will be available for all users on the current workstation. You can now either close the program or continue to calibrate another monitor.

Finally, after calibration is complete for all monitors go into Windows Color Management and make sure Use my settings for this device is enabled for all monitors. This will ensure that programs like 3D Lut Creator will use the correct ICC profile for color representation.

Profile Management

An important final step is to copy the newly generated ICC profile/s to the server. ICC profiles are stored in C:\Windows\System32\spool\drivers\color and they need to be copied to RESOURCES_OLD\02_ASSETS\0000_COLOR\%WorkstationName%. If there is no folder with the name of the workstation that has been calibrated, you will need to create one. For example VMWORKSTATION01 or BGWORKSTATION01.

This step is necessary to keep track on calibration and also to help with further creation of ICC profile based LUTs for use in 3ds Max and Fusion. More on this in the next topic.