Pro Digital Gear BLOG!

If you are serious about controlling color output it is critically important  to have a monitor that faithfully displays color to a known standard. It is the single most important step you can take on the way to to reaching the holy grail of having the colors displayed on your monitor match printed (or other) output.

Reading posts on other web sites and fielding questions about color management here at Pro Digital Gear, I conclude that there is a lot of confusion about monitor profiling. I hope to clear up some of the confusion with this post.

Monitor calibration and profiling is really a two step process but the steps are often intertwined when applied in monitor profiling hardware and software solutions. More about the solutions later. Before beginning calibration and profiling, you must be sure your monitor has been on long enough to have reached a stable condition. A good rule of thumb is to allow 30 to 45 minutes for a CRT display and 15 to 20 minutes for an LCD display to warm up.

STEP 1: Calibrate the monitor. Calibration puts the monitor in a known reference state that it can be returned to in the future.

STEP 2: Create a profile for the monitor. This step creates a correction table for your monitor that ensures it is displaying color accurately when compared to industry standards.

Step 1 involves establishing some parameters and then adjusting your monitor using it’s controls to come as close as possible to the targets. The three target values are:

Luminance:  Usually specified in candellas/square meter. Reasonable target values are  95 for CRT monitors and 130 for an LCD monitor. Not all monitors will achieve these numbers.

NOTE:It is important not to select the greatest luminance value for a particular monitor because as it ages, the ability to reach the target luminance will decline and subsequent profiling will be effected.

Tonal Response Curve (TRC) or Gamma: This target should be set at 2.2 for either Mac or PC based systems.

White Point: A suggested value is D65

The colorimeter or spectrophotometer and software package that came with it will lead you through the necessary calibration steps. Not all monitors have the same controls particularly when it comes to establishing the white point. Some monitors wrill only have white point “presets” to choose from while others will allow you to individually adjust the red, green and blue channels to the desired white point.

After establishing the desired target values above, profiling  of the monitor will be accomplished using a spectrophotometer or a colorimeter and the software that came with it. It is in this step 2, that the color corrections are determined and a color profile created for your monitor. The color profile will be installed in the operating system.

A word of caution.  Any images that you have adjusted and printed successfully before profiling  your monitor may now look “unacceptable” because you have changed its display.  If it is important that you can print them identically to the way they were printed in the past do not make any new color adjustments to them.

Once your display profile has been created, you can check that Photoshop is recognizing it by going to the edit color preferences menu and from the RGB work space scroll to “monitor RGB”. You should see the name that you gave your profile. Note do not select this as your RGB work space. You should also be aware that not all software that can display images makes proper use of the display profile, so your images may have a different color look when viewed in non “color aware” software. You should only make color or tonal range adjustments to your images on your properly profiled monitor and using “color aware” software such as Photoshop.

You must periodically re-calibrate and profile your display as they do drift with time. Most particularly CRT displays. Weekly or at least monthly recalibration and profiling is recommended.

There are several monitor profiling packages available. I personally like the Eye-One Display 2 from X-rite.

…John