Subtractive Colour Mixture
Transmittance Transmittance: = ( ) out / ( ) inTransmittance: = ( ) out / ( ) in Internal transmittance = External transmittance - ReflectanceInternal transmittance = External transmittance - Reflectance Optical DensityOptical Density
Optical Density
Transmittance change with filter thickness
Transmittance of red/green/blue and cyan / magenta / yellow filtersTransmittance of red/green/blue and cyan / magenta / yellow filters
Subtractive colour mixture Yellow plus magenta filters transmitt redYellow plus magenta filters transmitt red
Subtractive colour mixture Yellow plus cyan filters transmit greenYellow plus cyan filters transmit green
Subtractive colour mixture Magenta plus cyan filters transmit blueMagenta plus cyan filters transmit blue
Combination of the filters Three filters of different thickness
Subtractive mixing with pigments Surface with pigment particlesSurface with pigment particles –Regular reflextion from surface –Absorption in pigment particles