CTB filters are designed to increase the color temperature (measured in degrees Kelvin) of a light source. GamColor CTB filters will raise the color temperature of an incandescent light source to match the color temperature of a daylight source such as a strobe or HMI lamps.
Full CTB will typically convert a 3200 K light source to 5500 K, or normal daylight. Because incandescent lamps vary in color temperature and with the operating voltage, GamColor offers seven graduated steps of CTB filters to help you achieve the proper color balance.
When color temperature is very critical a color light meter should be used. The meter will give the color correction in "mired shift".
GamColor is deep dyed polyester – the color is linked molecularly into the polyester. There is a distinct advantage to this process over surface coated polyester. The deep dye process is more difficult to remove because it disturbs the molecular structure. Once the color is placed into the film it becomes difficult for color to evaporate or depart from the polyester base. In contrast, surface coated polyesters are more susceptible to fading when exposed to heat since the coating is merely placed on the surface and can readily evaporate.
Polyester melts at 480° F while polycarbonate-based gels melt at approximately 380° F. Polyester does not soften until it reaches 400° F, whereas polycarbonate softens at about 270° F.
Please note that the color filter samples shown on this web site are a suggestion of the color. You should always make your final selection with a GamColor swatchbook in hand.