Scotopic curve

A scotopic curve is a graphical representation of the sensitivity of the human eye to light under low-light conditions, such as at night or in very dimly lit environments.

  • A scotopic curve shows the minimum amount of light required for the human eye to detect a stimulus at different wavelengths of light. The curve is based on the response of the eye’s rod cells, which are responsible for detecting light in low-light conditions.
  • Unlike the photopic curve, which peaks at around 555 nanometres (green-yellow light), the scotopic curve peaks at around 507 nanometres (blue-green light). This means that in low-light conditions, our eyes are most sensitive to blue-green light.
  • Scotopic and photopic curves have different units of measurement.
    • A photopic curve uses units of luminous flux, which is a measure of the total amount of visible light emitted by a source.
    • A scotopic curve, on the other hand, uses units of luminous intensity, which is a measure of the brightness of a light source per unit of solid angle.