Why Objects Appear the Color They Do
Visible Light and Color Spectrum
- Visible light is made up of a spectrum of colors from red to violet.
- Red: Longest wavelength, lowest frequency.
- Violet: Shortest wavelength, highest frequency.
- Memorize the order using ROY G BIV (Red, Orange, Yellow, Green, Blue, Indigo, Violet).
- White Light: Combination of all wavelengths.
- Blackness: Absence of light.
Factors Determining Object Color
- Wavelengths of Light contacting the object.
- Properties of the Object: Determines if light is absorbed, reflected, or transmitted.
Opaque Objects
- Do not transmit light (e.g., a cat).
- Reflect or absorb light.
- The color is determined by the light wavelengths reflected.
- Example: An object appears blue if it reflects blue wavelengths.
- Some objects reflect multiple wavelengths to appear a certain color (e.g., yellow cheese reflects red and green).
Transparent & Translucent Objects
- Transparent Objects:
- Transmit nearly all incident light.
- Example: Window glass.
- Translucent Objects:
- Transmit some light, partially see-through.
- The object's color is determined by transmitted wavelengths.
- Example: A green plastic bottle transmits green wavelengths.
Color Filters
- Purpose: Filter out specific colors, allowing only certain wavelengths to pass.
- Primary Color Filters: Allow one primary color (red, green, or blue) to be transmitted.
- Example: A green filter allows green wavelengths to pass; white paper through this filter appears green.
- Non-Primary Color Filters: Transmit wavelengths of the filter color and primary colors that combine to form that color.
- Example: Yellow filters allow yellow, red, and green wavelengths.
- Indigo filters allow indigo, blue, and red wavelengths.
This concludes the explanation on why objects appear as they do based on light and color properties.