Color Management for the Color Blind
Color management, the art and science of reproducing accurate skin tones, blue skies, red apples, and yellow bananas is a relatively painless process for about 90%-or-so of the human race. If you belong to the majority of the populous, own a decent monitor, printer, and a color calibration system - and actually take the time to use it – you should be able to faithfully render the color and tonality of the image you saw in the camera's viewfinder. For the remaining 10%-or-so of the population things aren't so easy because they are color blind, an erroneously named condition for people who cannot accurately differentiate between certain colors.
Without delving heavily into the details of color blindness (Note- I'm not really a doctor… though I've been known to dabble in surgery) let's just say it comes in several forms and can be inherited or caused by eye, nerve, or brain damage. Like many congenital medical conditions, the degree of color deficiency varies from one individual to another, and is ten-times more common in men as compared to the fairer sex.
Ladies- If your beau's tastes in shirt/tie combinations make you wince and/or he has a habit of barreling through red lights, have compassion for the poor guy because he's clueless. And for gosh-sakes wear a seatbelt.
Mom's a Redhead but According to Your Prints Her Hair is Blue
The human retina contains rods, which facilitate low-light vision, and cones, which process normal daylight as well as color data. The most common forms of inherited color deficiency are reduced sensitivity to red and green, followed by a less-common insensitivity to blue and yellow. The rarest form is cone monochromacy - the inability to discern color in any form – in which your world resembles a pre-Ted Turner black & white movie.
It's interesting to note under fast-action/panic situations – i.e. you're in the midst of a car crash – your vision momentarily switches to monochrome in order to process visual data as quickly as possible, and promptly returns to color as the dust settles.
Color deficiency is also somewhat quirky. As an example, a red-green deficient person might have difficulty discerning colors and/or hues on a printed page, yet have no problem deciphering the same color data on a computer screen or TV. Likewise, some color deficient individuals have no problem deciphering colors on synthetic materials or painted with acrylics, yet cannot process the same color data when printed on natural surfaces such as paper or wood. And certain color deficient individuals - anomalous tricromats - can also detect camouflage patterns designed to fool normal vision.
How to Make Mom a Redhead Again
If you are color deficient the fun & games come into play when you try printing photographic images. If you're lucky, you have a significant other who can tell you if your skies are too green or skin tones too magenta. Without that extra set of eyes you can be way off and never know it. The good news is we have more than a few suggestions on how to make mom a redhead again. And even if you aren't color deficient, chances are you'll learn a thing or two anyway, so read on.
The 'X' Factor
While there are no cures for color-deficiency, there are a few ways around the problem. A solution that works for individuals having trouble differentiating between red and green (protanopia) is the use of an X-Chrome lens, a red-tinted contact lens that is worn over the user's weaker, non-dominant eye. Depending on your unique deficiency level, the use of an X-Chrome lens can restore a decent level of color perception. How decent? Decent enough to pass the vision test for a pilot's license. For further details contact your local ophthalmologist.
Be Consistent From Start to Finish
One thing you must absolutely, positively do is calibrate your monitor on a regular basis, and this holds true for everybody regardless of how good your vision may be. If your monitor isn't up to spec, your prints will never look right. You should also actively shield your monitor against stray light – sunlight or otherwise – as stray light can influence your choice of color and contrast settings. Many manufacturers, including Eizo, LaCie, Panasonic, and Samsung, offer monitor hoods for select models. There are also third-partymonitor hoods available from Hoodman to fit most all standard-size computer screens and laptops.
The light you view your prints under is an equally important part of the equation. Whenever possible you should judge the color rendition of a print under the same lighting conditions it will be displayed under. A print judged under a tungsten light source will look noticeably different when viewed under daylight or fluorescent light. And again, this is true regardless of the accuracy of your color vision.
A variety of print viewing stations are available from GTI and Just in sizes ranging from 8x10" desktops to full-size mural viewing stations. Most viewing stations are balanced to D5000° (daylight), but can be corrected to match specific color conditions, i.e. D6500, Fluorescent, Tungsten, etc, by installing the appropriate lamps. By going these extra miles you greatly minimize many variables that ultimately cost you time and money.
Color by the Numbers
The first step in shooting a decent photograph - regardless of how good or bad your color vision may be - is to establish a proper exposure and white balance. The most accurate way to do this is by metering from a neutral gray card and/or a color patch target containing neutral patches alongside your main subject, making sure the card is reflecting the same levels of light as your subject. Once the correct exposure is established it's a matter of going by the numbers to establish a balanced color palate. A selection osf color targets and gray cards are available from Xrite, Kodak, DSC Labs, Calibr8 and LaserSoft.
Starting with a correctly exposed image file, open an image in Photoshop and using the Color Sampling Tool, click on an area containing the brightest highlight details and another containing the darkest recognizable shadow detail. Next, open the Curves dialog box. While keeping an eye on the RGB Info palette, select the Red channel and use the slider tool to adjust the shadow clipping point to about 7 (up from pure black, which is 0) and the highlight clipping point to about 245 (down from pure white, which is 255). Repeat this in the Blue and Green channels.
The exact numbers should be based on the dynamic range of the image and can vary a few points up or down. If you're not sure a few tests should help you establish the correct settings, and it doesn't cost anything to experiment. It's also a good idea to take the image up to pixel resolution, which makes it easier to identify the sweet spots of your highlights and shadows. And remember- Do not touch the actual Curves, just the RGB clipping points.
In most all cases you will immediately see a noticeable improvement in color saturation and color accuracy as you click on the Preview box. Color casts go away and the image becomes punchier with no loss of image quality. If you follow this procedure you can achieve accurate color even if your monitor was never calibrated, though we are in no way excusing you from this chore. Your final settings can be saved as an action and applied to all other images in the series. For further insight into this process, see "Professional Photoshop" by Dan Margulis.
Eizo Monitors- Nipping Problems in the Bud
It's not only color blind folks who have to deal with issues involving color deficiency. Graphic designers and others responsible for producing print and online materials geared for public consumption also have to deal with the problem. Just because you can read light-green text against a magenta background - or any other number of color combinations for that matter- doesn't mean the person reading it can. For color-deficient individuals, everyday signage, maps, and other forms of print and electronic communications can be downright daunting.
As a workaround solution to this problem, the Eizo Nanao Corporation, manufacturers of pro-level LCD screens, developed a user-oriented color viewing system called Color Universal Design (CUD), which can simulate the color rendition of screen images as they would appear to individuals inflicted with protanopia or deuteranopia, the most common forms of color blindness. Graphics can previewed onscreen as they would appear to color-challenged individuals, reducing the possibility of going to press with problematic color combinations.
CUD color technology is currently available in the Eizo FlexScan SX2461W, Eizo FlexScan SX2761W, and ColorEdge CG241W. If visual communication is what you do for a living, these monitors can prove to be a valuable investment if your designs are targeted towards public consumption. And all those guys in mismatched shirts and ties will thank you.
Just as the 'correct' exposure is not always the 'best' exposure, neutral color is not always the 'correct' color. What makes sunrise and sunset photographs so inviting is the warmth caused by sunlight streaming through the atmosphere from a low-angle. Once you neutralize a sunset you eliminate the magical qualities as well. Same goes for the blue cast of pre-dawn light and rainy days. So remember- Be judicious about how far you correct the color of light because neutral doesn't necessarily mean better.