Table 3-3.–Light Balancing filters Filter  color Yellowish Bluish Filter  number To Obtain 3200 K from: To Obtain 3400 K from: 81 3300  K 3510  K 81A 3400  K 3630 K 81B 3500  K 3740  K 81C 3600  K 3850  K 81D 3700  K 3970  K 81EF 3850  K 4140  K 82C+82C 2490  K 2610  K 82C+82B 2570  K 2700  K 82C+82A 2650  K 2780  K 82C+82 2720  K 2870  K 82C 2800  K 2950  K 82B 2890  K 3060  K 82A 3000  K 3180  K 82 3100  K 3290  K color balancing filter can be used to raise the color temperature 100 K. Light balancing filters affect the entire  visible  spectrum  of  tungsten  light  and  provide  an adjustment from one Kelvin temperature to another. When the color temperature of a tungsten light source is unknown, you can use a color temperature meter to determine it. When trying to determine what light balancing filter to use for producing a particular color temperature with a given light source, you may use the  following  methods: 1.   Refer to the scale on a color temperature meter. 2.   Refer to the tables in the Photo-Lab-Index. 3.  Consult  the  manufacturer’s  publication  for  a particular  filter  or  meter. 4.   Consult appropriate film or filter data sheets. Light balancing filters are Series 81 and Series 82. Refer to table 3-3 to determine light balancing filters that can be used to raise or lower the color temperature of a given color. CONVERSION   FILTERS Conversion filters are used in color photography when a significant adjustment of an exposing light is required to convert the color quality of the exposing light to the color temperature for which a film is balanced. Conversion filters generally come in two series. The 80 series of filters are blue in color and convert tungsten light to color qualities acceptable for use with daylight film. The 85 series of filters are amber in color and convert daylight to color qualities acceptable for use with  tungsten  film. The correct filter to use for a given situation with a given film can most accurately be determined by consulting  conversion  filter  tables  in  the  Photo- Lab-Index or reading the filter and film data sheets. COLOR  COMPENSATING  FILTERS Color compensating (CC) filters are used to adjust the overall color balance obtained from color film, particularly  slide  film.  Without  the  use  of  color compensating filters, improper color cast can result. For cameras, CC filters are normally used to color balance  the  light  from  sources,  such  as  fluorescent, tungsten, and mercury-vapor lights, and the “bounce” light reflected from colored surfaces. They are also used to balance lighting effects under unusual circumstances; for example, underwater lighting. These filters can be used to compensate for a known color deficiency of an unexposed color film. They can also be sandwiched (layered)  when  mounting  a  color  transparency  to compensate for an off-color hue. 3-5