Specific factors in understanding lighting

Fundamentals of Art and Design 3(1+2)

Lesson 10 :LIGHTING

Specific factors in understanding lighting

  1. Physics of light and color:
    • When white light is passed through a prism, the component colors are separated into clearly distinguishable bands.
    • When light hits something it may be reflected, absorbed, or allowed to pass through, depending on the degree of transparency or opacity of the material and on its surface qualities.
    • Light reflected from smooth surfaces such as mirror is bright and sharp, diffused when reflected from rough surfaces, such as brick.
    • Objects illuminated by small, sharp light sources show strong contrasts of light and dark, less contrast if the light source is broad and diffuse and almost no contrast if evenly lighted from all sides.
    • Shadows from objects lighted by small, sharp beams are usually hard, sharp and dark. Soft and spread out if the light source is broad. Diffused, multiple and overlapping if light comes from more than one direction.
    • The shape of objects can be emphasized or subordinated by the direction from which the light comes.

  2. Brightness of light:

    The following broad considerations should be kept in mind, while planning the amount of lighting needed for any specific task.

    • Bright light is stimulating, calls forth energy and makes us feel as though we should be up and about,
    • Low levels of brightness may seem relaxing and restful, romantic, dingy and depressing or even frightening, depending on the context.
    • Moderately bright light brings no pronounced feeling other than general well-being.
    • Balance, rhythm and emphasis come from appropriate distribution of quantities of light.

  3. Glare:

    Glare is to be avoided. Glare may be from exposed bright sources of light, incorrectly designed fixtures, too much light, especially from one direction and excessive contrast. The contrasting glare and gloom frequently encountered in night driving and too often in homes, are an eye- fatiguing combination. For close work, the working area should not be more than five times as bright as the darker part of the room and a ratio greater than 1:10 is undesirable in any place. But it is also fatiguing- both to the muscles of the eyes and the spirits of the occupants- to have every part of a room equally bright. Moderation in quantity and contrast of light is a sensible solution.

  4. Tips to avoid glare:
    • To avoid glare shade the lamp to screen it from the eye.
    • Do not place lamps and objects to be viewed too close together.
    • Provide a proper degree of illumination for the space to be seen.
    • Make use of frosted bulbs, opaque glass shades which diffuse and soften the light.
    • Glare also results when a bright light falls on a polished or glossy surface and is reflected from that surface to the eye. The shiny covers of books and magazines, glossy table tops or a mirror often cause glare.
    • With dimmers, brightness of light from almost any fixture can be instantly and smoothly adjusted from a candle- like glow to full brightness.

  5. Effective lighting for homes:
    • Enable us to see quickly and easily.
    • Prevent accidents, especially at such hazards as stairways.
    • Protect our health by minimizing eyestrain and by disclosing potentially harmful dirt.
    • Contribute to the attractiveness of our homes.
    • Sufficient and glare less light where ever needed for close work is essential.
    • Adequate, pleasant general illumination to reduce fatiguing contrasts.
    • Good illumination at danger points, for safety.
    • An overall pattern that is rhythmic and balanced, is essential.
Last modified: Saturday, 18 February 2012, 11:43 AM