Display calibration helps home video displays deliver the best possible image quality. Most televisions and home video systems display wildly inaccurate images when first installed. According to Sound and Vision, manufacturers deliberately boost the brightness, contrast and color settings to unnaturally high levels to show these devices off amidst the fluorescent glare of an electronics showroom. Once the display enters a home theater or living room environment, calibration corrects errors such as distorted picture geometry, artificially sharp edges and overemphasized red tones.
The end result of a proper calibration (depending on the type of display you’re using) will result in a substantial savings in energy consumption upwards of 80%, extend the life of your display upwards by 100%, widen the viewing angle up to 100% (or sometimes even more), and most importantly, safeguard your vision from the overly bright images (most TV tend to be around 750 ftL in brightness out of the box, yet they are not supposed to be higher than 35 ftL for the health of your eyes… believe it or not, at the movie theatres, the brightness level almost never go beyond 16 ftL, which means your TV out of the box is usually 1,000% brighter than what it’s supposed to be)
The Imaging Science Foundation and THX, have helped home theater owners and electronics manufacturers understand and make use of proper image calibration since its founding in 1994. ISF and THX-certified calibration technicians specialize in adjusting the levels of a projector or television to its environment by balancing the color, contrast and brightness setting both against the room lighting and against each other.
Types and Costs
The amount of money a home theater owner will spend on an display calibration depends of the extent of the service and the type of video device. ISF and THX recommends that calibration technicians charge US$375 display calibration as of June 2010. These entry-level rates include calibration of the user-serviceable image control levels and the the unit’s gray scale response. Advanced calibration techniques applied to a deluxe front-projector setup can cost US$1,000 or more, as of June 2010. The purchaser might pay a travel fee as well.
Tools and Measurements
The calibration technician uses calibrated colorimeter for measuring and adjusting the various factors that influence image quality. Test pattern generators such as the THX Calibration Blu-ray run the set through a series of tests so the technician can gauge and adjust each video level.
After selecting the most accurate image preset the user menu offers as a starting point, calibrators adjust the delicate balance between brightness, which determines the image’s maximum black level, and contrast, which determines its maximum white level. The calibrator then adjusts color and tint using industry-standard color bars while looking through blue, green and red filters. Finally the calibrator adjust the gray scale from a test image of gray rectangles.
Home theater owners will note dramatic changes in picture quality following a proper, comprehensive calibration. At first the image may seem inappropriately muted or dark, but in fact these new levels represent the image as the filmmakers intended it for viewing in the dimly-lit environment of a movie theater. For example, most TVs are set to around 160 foot-Lambert of brightness out of the box where a properly calibrated display should not go beyond 35 foot-Lambert in brightness. Once viewers get used to the calibrated image they will notice the lesser quality of an uncalibrated system.
sources: eHow, Imaging Science Foundation, THX, Society of Motion Picture & Television Engineer.