Table 3-4.–Filters and Exposure Increase for Making Color Pictures by Fluorescent Light Type of fluorescent lamp Daylight Type of color film Tungsten I Cool  White 30M + 2/3 f/stop Deluxe  Cool  White 30C + 20M + 1 f/stop Standard  Warm  White 40C + 40M + 1 1/3 f/stops Deluxe  Warm  White 60C + 30M + 1 2/3 f/stops 50M + 60Y + 1 1/3 f/stops 10M + 30Y + 2/3 f/stop 30M + 20Y + l f/stop 10Y + 1/3 f/stop White Daylight 20C + 30M + 1 f/stop 40M + 30Y + 1 f/stop 40M + 40Y + 1 f/stop No. 85B + 30M + 10Y + 1 f/stop Whenever   possible,   you   should   conduct photographic tests in advance, using the type of light you expect to encounter. Consult the Photo-Lab Index for the most accurate filtration to use for your film, filter, and lighting situations. Table 3-4 provides an example of a good starting point for test exposures. When in doubt, you should use a filter that provides for average correction. For daylight film, you should use a 30M filter with a 2/3 f/stop exposure increase. For tungsten film, you should use a 50R filter and a 1 f/stop exposure increase. CC  filters  may  be  used  alone  or  in  various combinations.  However,  when  you  use  them  in combination,  the  maximum  number  of  filters  in  front  of a lens should not exceed three. More than three filters adversely affect image quality. When combining CC filters, you should avoid creating a neutral density effect. Neutral density is caused when all three of the primary colors are present in the combined filters; for example, a cyan (blue and green) filter and a red filter. CC filters are available in blue, green, red, yellow, magenta, and cyan. Each color is available in a range of densities. The color and density of a CC filter are identified in the filter designation, such as CC50Y. The CC indicates color compensating, the 50 indicates a peak density of 0.50 to blue light, and the Y is the first letter of the filter color-yellow. The peak density of a CC filter refers to the maximum absorption of the color of light that is complementary to the color of the filter. CC  filters  are  available  only  in  gelatin  squares. The color star (fig. 3-4) indicates various color relationships of color compensating filters as follows: 1. Complementary colors are opposite each other: cyan is complementary to red, yellow is complementary to  blue,  and  magenta  is  complementary  to  green. 2.   Any one color is a combination of the two colors adjacent to it: R = M + Y Y  =  R  +  G G  =  Y  +  C C  =  G  +  B B  =  C  +  M M = B + R C302.24 Figure 3-4.–Color star. 3-6