Colour Temperature On LCD Monitors
The colour temperature of most LCD monitors can be adjusted via the on screen display (OSD) menu. How colour temperature is adjusted differs from product-to-product. Some ask for kelvin values to be set while others ask the user to pick from terms such as 'blue' or 'cool'. Whatever the system, one thing they all have in common is that reducing the colour temperature gives the entire screen an increasingly reddish cast, while increasing the colour temperature makes the colour cast increasingly blue.
If the options for selecting colour temperature are 'blue' and 'red' or 'cool' and 'warm', choose 'red' or 'warm' to lower the colour temperature and 'blue' or 'cool' to raise the colour temperature.
Terms such as 'blue', 'red', 'cool' and 'warm' may be easier to understand but they don't make it easy when you need to adjust the monitor to a specific colour temperature (Kelvin value) so if you want to specify precise Kelvin values when adjusting the picture, you'll need a monitor which uses this scale rather than descriptive words.
A colour temperature of 6500 K is standard for ordinary PC use and for the sRGB standard. Most LCD monitors offer a setting of 6500 K among their colour temperature options. If a monitor offers an sRGB mode, setting it to this mode should present no problems. In most cases, even products whose colour-temperature settings use terms like "blue" and "red" will be adjusted to close to 6500 K for standard mode, although accuracy may be lacking. The LCD monitors on some laptop PCs are set to higher colour temperatures.
A colour temperature of 5000 K is standard in the field of desktop publishing for printing or publishing. This is because pictures are intended to reproduce the look printed colours have when viewed under conditions close to direct sunlight.
The above shot shows a white image under the colour temperatures 5000, 6500, and 9300 K (from left to right). Since the photo was shot with the colour temperature of the digital camera set to 6500 K, white in the 6500 K image in the center appears pure white. It appears with a more red tone in the 5000 K image and blue in the 9300 K image.
When changing the colour temperature setting for the camera, the look of whites in those images will be shifted accordingly: the image with a colour temperature lower than the set value will appear reddish and the one with a higher colour temperature will look bluish.
In the above image, the sample colour bars are displayed at colour temperatures of 5000, 6500, and 9300 K (again, from left to right).
As demonstrated, when colour temperatures change, the apparent colour of the white, or the overall colour balance, is affected. Colours at lower colour temperatures tend to appear warm; at higher colour temperatures, they tend to appear cool.
More Accurate Control
In situations where colour reproduction significantly affects the final quality of the work, retouching images for example, managing LCD colour temperatures with greater accuracy is critical. For this reason, it's important for photographers to use an LCD monitor that supports colour management based on hardware calibration. More advice on calibration and why it's important can be found in the EIZO ColorZone technique and feature areas.
As well as adjusting LCD monitors with calibration software care must be taken when setting up a work environment as lighting can change how colours appear.
Another useful tool is an LCD hood which is attached to the top and sides of an LCD monitor to reduce the effects of environmental lighting on the screen display. By fitting one, it makes it possible to view the true screen colours while working on the LCD.
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