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Can You Color Manage an LCD-backlit Display?

Answered by Jay Nelson, Editor and Publisher, Design Tools Monthly

Question:

Several companies, including HP, Apple and Eizo, have released new LCD displays that use LEDs as backlight, instead of the traditional fluorescent light. I understand that LEDs last longer and use much less energy than fluorescent lights, but I've also heard that LED lighting affects my ability to profile the display for accurate color management. True?

Answer:

It doesn't just affect your ability, it torpedoes it. It's true that the current crop of display-calibration devices work well with CRTs and fluorescent-lit LCD displays, but LEDs are a different kind of animal. To understand the situation, I had a chat with Chris Murphy, color expert and co-author of Real World Color Management (Peachpit Press). Here’s what I gleaned from our conversation:

First, let's understand the jargon:

LCD: Liquid Crystal Display. The most common flat-screen display, which requires a light source to shine from behind to illuminate its crystals.
LED: Light Emitting Diode. They come in several colors, including white.
CCFL or fluorescent backlighting: basically, fluorescent tubes.

Here's the situation:

Some manufacturers use white LEDs, other manufactuers use RGB LEDs, and still others use CMY LEDs. The problem is that each of these light sources produces a different spectral output, and current colorimeters don't know how to deal with that. They’re all designed for CRTs and/or LCDs with CCFL (fluorescent) backlighting.

Chris says the closest device we have is Pantone's ColorMunki Create, a spectro-radiometer that, along with X-Rite's EyeOne Pro, accurately measures RGB primaries on these LED-backlit displays, but does not accurately measure shadows. So, it kinda works, but kinda not.

Other calibration devices rely on color lookup tables to understand the behavior of a CRT or LCD display. Those tables currently don't include LED-lit LCD displays.

What's a color geek to do?

If you're going to buy an LED-lit LCD display, your best option is to buy one that includes its own calibration device. Those are custom-built for that exact display, and so do not need to "understand" the output of other displays. Unfortunately, as far as I know only HP's DreamColor display includes a colorimeter.

This question was answered by Jay Nelson, Publisher & Editor, Design Tools Monthly. We love DTM's tips and advice and think you will, too. For a free sample PRINTED issue, contact Design Tools Monthly at 303-543-8400, e-mail info@design-tools.com, or go to their website: www.design-tools.com.