Explain the process of color subtraction?
Explain the process of color subtraction?
Colour subtraction:
- The process in which some wavelengths of an illuminating light source are absorbed by pigments in an object, While the remaining wavelengths are reflected.
- A pigment is an optically active substance which absorbs most of the colours of white light and selectively reflects one or more colours. These pigments have no colour. The colour gets activated only when the pigments are exposed to white light.
We will understand this with few examples:
(a). Let us take the example of a cricket ball that is made up of a material that can absorb red light. When the children are playing with this ball in the sun. The ball will be a cyan (peacock blue) colour.
The logic behind this is as follows:
White light is composed of three primary colours,
White light – Red
(Red + Blue + Green) –Red
Blue + Green +Red - Red
Blue + Green = Cyan.
We subtract red from white light because the ball can be any colour except red.
(b). Similarly, if children are playing with the same ball in a tallow floodlight, it will appear green:
Yellow light – Red
(Red + Green ) - Red
Red + Green – Red = Green
Thus, the colour of an object in different light can be determined by the method of colour subtraction.
Colour subtraction:
- The process in which some wavelengths of an illuminating light source are absorbed by pigments in an object, While the remaining wavelengths are reflected.
- A pigment is an optically active substance which absorbs most of the colours of white light and selectively reflects one or more colours. These pigments have no colour. The colour gets activated only when the pigments are exposed to white light.
We will understand this with few examples:
(a). Let us take the example of a cricket ball that is made up of a material that can absorb red light. When the children are playing with this ball in the sun. The ball will be a cyan (peacock blue) colour.
The logic behind this is as follows:
White light is composed of three primary colours,
White light – Red
(Red + Blue + Green) –Red
Blue + Green +Red - Red
Blue + Green = Cyan.
We subtract red from white light because the ball can be any colour except red.
(b). Similarly, if children are playing with the same ball in a tallow floodlight, it will appear green:
Yellow light – Red
(Red + Green ) - Red
Red + Green – Red = Green
Thus, the colour of an object in different light can be determined by the method of colour subtraction.
