Color Temperature Adjustment Filters (CTO/CTB)

Color Temperature Adjustment Filters are used in a wide variety of lighting applications including architectural and cinematic lighting, analytical test equipment and solar simulators, surgical room lighting, medical imaging, security spotlight illumination and more. They are used to selectively transmit some specific spectral portions of the light so as to be able to adjust or change the color appearance of the light for aesthetic or technical illumination reasons.

Color Temperature Adjustment Filters can be used to give lighting a warmer or cooler color hue as well as change one light source’s output to look like another, i.e. converting LED or tungsten light output so it looks like natural sunlight or managing the color temperature distribution of LED’s with a selection of adjustment filters to deliver a more consistent color temperature output without yield fall out and need for LED “binning”. Originally, color temperatures did refer to the actual temperatures of thermally radiant sources of light in degrees K and an associated standard “color” of light generated like incandescent bulbs with filament temperatures of near 2400K and “warm white” color output. LED’s, LCD’s, OLED’s and many light emitters don’t rely on a thermally radiant process for light generation so the use of color temperature is now just a standardized reference describing a perceived broadband light output “color” in the industry.