About colour brightness
- In a general sense, brightness is an attribute of visual perception in which something appears to an observer to be radiating or reflecting light.
- Colour brightness increases as lighting conditions improve, whilst the vitality of colours decreases when a surface is poorly lit.
- Optical factors affecting colour brightness include:
- Material properties affecting colour brightness of a medium, object or surface include:
- Chemical composition
- Three dimensional form
- Perceptual factors affecting colour brightness include:
- The term brightness is best understood when associated with a specific colour model.
- Examples of colour models include:
- The HSB colour model uses the term brightness alongside hue and saturation.
- Some colour models don’t use the term brightness at all.
- When we change from one colour model to another, it’s best to change our terminology as well
- When an observer asks themselves about the colour of something, they will often unconsciously think in terms of a particular colour theory associated with:
- Spectral colours with names associated with atmospheric rainbows
- Pigments, where powders are mixed with water, oil or acrylic to produce different colours
- Objects and surfaces which transmit, reflect and absorb wavelengths of light in different proportions
- A broader vocabulary of names can be used to describe colours such as dark red, vermilion, golden yellow, lemon yellow, pale yellow, greenish-yellow, chartreuse, leaf green or light green.
- A colour model derived from a theory of colour allows for a more exact and reproducible approach to colour.
Brightness, Intensity, amplitude
In this dictionary:
- Brightness is used in connection with the perception of colour.
- Intensity is used in connection with the amount of light that is produced by or falls on an object.
- Amplitude is used in connection with the properties of electromagnetic waves.
Colour brightness and light intensity
- The perception of colour in the world around us depends on the spread of wavelengths that reach the eyes of an observer.
- The perception of brightness of a colour depends on the amount of light an object emits, absorbs or reflects.
- The perception of brightness depends on the amplitude of the oscillation of light waves. Amplitude is a measure of the height of light waves from trough to peak.
- The amplitude of a light wave or the intensity of light can be thought of in terms of the volume of photons that it carries.
- Increase the amplitude of a wavelength of light and the volume of photons falling on an object will increase its apparent brightness to an observer.