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Artificial Light

And then there was light! It’s a 24/7 existence. Work all night, sleep all day. We humans are no longer tied to the light of the sun. Nor do we light our world with candles, oil or gas! Thomas Edison invented the light bulb in 1879 and we have been lighting up ever since. We can use electricity to keep going whenever we want if we are willing to pay the price. Artificial lights have a lamp or fixture wired to bring electricity to the bulb. When electrical current comes to the bulb, the bulb glows or emits light that is measured in foot-candles or lumens per square foot. There are thousands of fixtures and bulbs. The closest artificial light to sunlight is the incandescent bulb. Standard 100 watt bulbs produce 1600 lumens. Fluorescent bulbs last longer and use less energy than incandescent. We have emergency lighting (20 foot candles for safety), general lighting (40-60 foot candles to see at night), mood lighting (for atmosphere), accent lighting (for sparkle), and task lighting (for reading and writing, at 80-200 foot candles).

Light up your life!!!

Activity 1 Bulb Identification

Make an hourly chart like the one shown from 6:00pm to 10:00pm in your house with the hours on the left and the types of bulbs across the top. Each hour, mark how many lights are on in your house, what types of bulbs they are, and what the lights are used for. Use a yellow marker to highlight those bulbs that could be changed to more efficient types of bulbs that still give off the same amount of light but use less energy. To save energy, use compact fluorescent lamps that burn longer and use less energy. Choose task lighting specific to the task at hand rather than illuminating an entire room! Use three way bulbs so you can self-select how much light you need. Take a look at Luminaires as Mediators Between Space and Light to see how different light bulbs (sources) deliver different directions and ranges of light. Make a sketch in your journal and diagram the different source types and light throws.

Activity 2 Lamp Study

Visit a hardware store. Look at all the light bulbs that are available. The bulbs differ in shape, size, watts, lifespan and cost. All of these features must be taken into consideration before selecting the right bulb for the right use for the right fixture. Using the web links, internet or other resource, research lamp types. Find out where different lamps are used. Look at Lamp Types. Sketch and label five different light bulb types. List their characteristics. Paste these in your journal.

Activity 3 Light a Bulb!

In this activity, you will actually construct and light a light bulb! All you need is two AA batteries, a metal clamp ….Take a look at the full exercise here on the ITSI Lighting a Bulb. Take a picture of your bulb and post it to the gallery!

Activity 4 The Color of Light

Sunlight is considered to be warm light with its full spectrum, or rainbow, of visible colors. Direct sunlight is the whitest. Indirect sunlight as in a northern painting studio is a blueish light. In addition, lamps of artificial light give off different colors of light. Some light bulbs are considered warm or in the sunlight range. Other lamps are considered cool or blue. When light, natural and artificial mix, it causes us to perceive color differently. Take a look at this additive color experiment to learn how mixing color, unlike mixing pigment, leads to a whiter light.

Activity 5 Artificial light and Photometrics

Light engineers, architects and interior designers specify certain types of lamps to light spaces. While choices of lamps may be based on looks, style, and form, designers calculate light function using mathematical formulas to fit the amount of light needed in a space with its function and material makeup. Turn on a lamp in a dark room. You can see for yourself that the light at the lamp source is the brightest with the amount of light falling off away from the lamp. Take a look at Photometric Quantities in Space to see different lighting terms and equations demonstrating lamp sources, light falling off, and illumination , or light falling on surfaces. Note that the amount of light from the lamp is recorded in lumens, or measure of brightness, while the amount of light that reaches the working surface ( your table, your book, the room, etc.) measures illuminance, or light received at a certain point, in lux. Make a sketch in your sketchbook labeling the light at the source (or sources) and the light on the working surface. Draw the lumens curve to show how the light falls off at distances from the source. Record acceptable lux levels as listed below:

Public areas with dark surroundings 20 – 50
Simple orientation for short visits 50 – 100
Work areas where visual tasks are occasionally performed 100 – 150
Warehouses, Homes, Theaters, Archives 150
Easy Office Work, Classes 250
Normal Office Work, PC Work, Study Library 500
Remember, without light, natural or artificial, we cannot see!


  1. 24 / 7 means:

  2. What two parts does a light have?

  3. A foot candle is:

  4. An incandescent bulb looks most like sunlight.

  5. Fluorescent bulbs are less efficient than incandescent bulbs:


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