How light can influence your images
There is a great variety in the color makeup of light that appears white. Direct sunlight at noontime is an almost perfectly balanced light source—it contains all colors in nearly equal quantities. But it will change dramatically either it is overcast, morning or evening. The color appearance of objects then changes dramatically. This happens as well under various artificial light sources.
Professionals in the visual industry are well aware of how light affects their work, and how difficult it is to control, reproduce, or compensate. The same color temperature effects apply to computer monitors and any devices using light (projectors, TV, etc) as their source.
In the desktop publishing industry, it is important to know a monitor’s color temperature. Common monitor color temperatures (along with matching standard illuminants in parentheses) are 5000 K (CIE D50), 5500 K (CIE D55), 6500 K (D65), 7500 K (CIE D75), and 9300 K.
Color matching software, such as Color Navigator that comes with an Eizo monitor, can measure a monitor's color temperature and then adjusts its settings accordingly. This enables on-screen color to more closely match the printed color.
D50 is scientific shorthand for a standard illuminant: the daylight spectrum at a correlated color temperature of 5000 K. Similar definitions exist for D55, D65, and D75. Designations such as D50 are used to help classify color temperatures of light tables and viewing booths. When viewing a printed material at a light booth, the light must be balanced properly so that the colors are not shifted towards the red or blue.
What color temperature or viewing standard should I use then? It is all relative!
The graphic arts & printing industry established a standard called ISO 3664 to minimize such color variations. The standard dictates that when viewing prints, a light source that replicates the D50 light source should be used.
It is important to note that not all 5000K light sources have the same chromaticity as an acceptable D50 light source! Nor all D50 light are necessarily acceptable D50 illuminants. The reason is that due to a phenomenon called metamerism, different light spectra can result in the same apparent light color, despite creating vastly different results in color rendering.
The D50 is similar in concept to but differs from D65 which is used as the standard daylight illuminant. Although both are considered natural daylight simulators, there are some significant differences when it comes to the spectrum as well as color point.
As shown in the graph above, it is clear that the D65 spectrum is more blue-biased than D50. Subjectively, D50 will appear "yellower" when compared to D65.
Galleries and museums use much warmer illuminants. Sotheby's recommends that "the light source must be baffled to reduce glare, the colour temperature should be a warm 2700k and the CRI above 95 as for the picture light to ensure best and true visual impact of the artist’s work."
A 5000K might seem too harsh and cool to view artwork (painting, sculptures, installations), despite that it is closer to "natural white" in nature. Our eyes don't like the harsh brightness of this color temperature and this is why we prefer sunglasses!
To achieve a controlled color across all aspects of the viewing and reprographic processes, you must implement standards and quality control procedures (color viewing conditions, measurement, standards for proofing, and printing processes). This can be overwhelming, and our team of G7 Certified can help you achieve the best workflow. We have access to the best products in the industry, a team of experts who can resolve any problems, and connect you with the latest technologies available.
Spectraflow East team