Colour Filters
- White light is a mixture of all the colours of the spectrum
- Each colour has a different wavelength (and frequency), making up a very narrow part of the electromagnetic spectrum
- White light may be separated into all its colours by passing it through a prism
- This is done by refraction
- Violet light is refracted the most, whilst red light is refracted the least
- This splits up the colours to form a spectrum
- This process is similar to how a rainbow is created
White light may be separated into all its colours by passing it through a prism
Colour Filters
- Colour filters work by absorbing certain wavelengths and transmitting other wavelengths
- These certain wavelengths correspond to certain colours
- When white light passes through a coloured filter, some colours are absorbed whilst others are able to pass straight through
- For example, when white light passes through a red filter:
- Red light is transmitted
- All the other colours are absorbed
- The colour that is transmitted is the same colour as the filter
A red filter transmits only red light and absorbs all other colours of light