Introduction

In this post, we will use Argyll CMS and dispcalGUI to calibrate a monitor in Mac OSX.

Calibration goals

Monitor calibration is a must have for any photographer. The goal when you calibrate your monitor is to have color references known by everyone (humans and software), you will display “true” colors.

Each monitor is not equal regarding color rendition. For example, some monitors are able to display more color shades than others. Remember that monitor calibration is not magic: if your monitor has an average quality, the calibration will improve the displayed color but will not help to display colors that your monitor is not able to render.

Anyway, a calibrated monitor will help you a lot to know how the printed color will render.

Softwares

In this article, we are using two software (running Apple OSX 10.6.3):

  • Argyll CMS v1.1.1: download here. It is a free calibration software.
  • dispcalGUI v0.3.8.0: download here. It is a graphic user interface for Argyll CMS.

These two software are free and are also available for Microsoft Windows.

To use these software, you need a calibration device. I’m using a device provided with Monaco Optix XR that I bought few years ago. It is a X-Rite DTP 94. I have found Argyll CMS because the software provided in the Monaco Optix XR package is not working with Apple OSX 10.6… And I am happy to have found it because it is as powerful (but less easy to use) than other available software that cost more than 200$.

Calibration

First, install the software, following dispcalGUI quick setup guide.

Before starting the calibration process, your monitor must be turned on for at least 30 minutes, otherwise the color rendering will change before the screen is warm. You should also turn off your screen saver and your energy saving settings: you do not want to have you monitor or your computer turned off while the calibration process is running!

Launch dispcalGUI.

You can plug your calibration device, it will be automatically detected by dispcalGUI.

dispcalGUI

dispcalGUI, click on the image to see it larger

Define these settings in dispcalGUI:

  • Select “Photo” in the Settings combo on top, it is a good starting point for other parameters
  • Whitepoint: select 6500°K. If you have an high quality monitor (EIZO brand for example), you can select 5000°K.  This is the light temperature used in fine art exhibitions. It is also the best temperature to compare printed colors with your monitor colors. Nevertheless, 6500°K is supported by all monitors and provides a good color rendition.
  • White level: Other, 120cd/m². It is a good brightness if you are working in a room not too dark. If you are working in a dark room, define a White level of 100cd/m².
  • Do not change the black level (Minimal).
  • Gamma setting: 2.2. The default value is 2.4. After a reader sent me a comment regarding the default value of my EIZO monitor (2.2), I am now using this new value.
  • Black output offset: if you have a high quality monitor, set it to 0%, you will have a better dark color shades. Otherwise, use the default value of 100%.
  • Profile type: “Curves + Matrix”. If you are selecting a LUT profile (slightly better profile quality), Lightroom and Photoshop colors rendition could not match.
  • Testchart file: photo.

You are now ready to calibrate your monitor!

Click on “Calibrate and Profile”.

X-Rite DTP 94Center your device on top of the displayed window, like shown on the picture above. Then the process continues in a terminal window.

Argyll CMS menuUsing a LCD screen, we will use two options in Argyll CMS:

  • 2) White point: setting your monitor color temperature
  • 3) White level: setting your monitor brightness

Start by pressing 2 on your keyboard. Your calibration device will continuously calibrate your monitor. The goal is to have a DE close to 0 by changing your monitor color gains:

RGB Colors gainsIn this example, I have an almost perfect DE (0.1).

During your monitor setting, Argyll CMS helps you to find the color gains. For example R++ means that you must increase the red color gain. For information, on my EIZO S2410W, I can adjust color gains in this menu: “Color” > “Gain”.

The next step if the white level setting. Press 3 on your keyboard. The setting is easier to achieve than the white point setting. Argyll CMS displays the target brightness and the measured brightness. You have to increase or decrease your monitor brightness to reach the target (120).

If you cannot set the white point or the white level in your monitor, just skip the related menu option.

It is time to launch the calibration process. Press 7 on your keybord (Continue to calibration).

You have time to drink a coffee… It is a long process…

Once the calibration is done, you will be able to install your new profile. Before doing that, it is interesting to try the color rendition with your new profile versus your actual profile. You achieve that by selecting or deselecting the first option of the window (Preview calibration).

Conclusion

Your monitor is calibrated! If it is the first time you are working with a calibrated monitor, you will not like the rendered colors, because they are less saturated. It is normal as default settings for monitors renders highly saturated and contrasted colors to match TV rendition that are pleasing people. Once you will be used to your new calibrated monitor colors renditions, you will not be able to work again on an uncalibrated monitor!

Now, you have reference colors. That will helps you a lot for your prints.

Updates:

  • August 21th, 2010 : change of the gamma level value used.


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