Electric Light

Visit a hardware store. Look at all the light bulbs that are available. The bulbs differ in shape, size, watts, lifespan, and cost. It is important to select the right bulb for the right use for the right fixture. There are thousands of fixtures and bulbs. The closest artificial light to the whiteness of sunlight is the incandescent bulb. Standard 100-watt bulbs produce 1600 lumens. Fluorescent bulbs last longer and use less energy than incandescent. The three most common bulbs for residential lighting include the incandescent, fluorescent and LED. It is important to chose the right bulb with the right color and amount of light and the best use of energy for each situation. Commercial and Industrial lighting uses other kinds of stronger, longer lasting bulbs such as halogen and High Intensity Discharge. Use this chart of Basic Bulb Types to identify bulb use in your house. Emergency lighting is ten foot-candles for exit safety. General lighting is 40-60 foot-candles. Task lighting ranges from 80-200 foot-candles depending upon the task. Additional types of lighting include mood lighting for atmosphere and accent lighting for focus, sparkle or playfulness. Also, different bulbs in different lamps give direct, indirect, or diffuse light depending upon filters, lenses, position and location. Using the web links sketch five different light bulb types. List their characteristics. Paste these in your journal.

Make an hourly chart like the one shown from 6:00 am to 10:00 pm in your house with the hours on the left and the types of bulbs across the top. Each hour, mark the number of lights on in your house, what types of bulbs are used, and the purpose of for the lights. Use a yellow marker to highlight bulbs that more efficiently 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. Or choose LED lights. 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. After you chart the bulb types, look at the amount of watts each bulb uses. Use the energy equation to find out how much energy has been used.

Energy = wattage x time

Chart your energy use of light!

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!

Sunlight is considered a 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 blue. 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. Make a white light diagram in your journal. In addition, the color temperature, or hue, of the light influences the color we see. These hues are color temperature are measured in degrees Kelvin. Check out the Kelvin Color Temperature Chart to see how different bulbs react inside and outside. Surprisingly color temperature of the same lamp may vary from inside to outside in natural light!

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. Location and function are also key. Should the light be in the ceiling, mounted on the ceiling, or hung from the ceiling. Mood lighting is often in the ceiling or located on the floor shining up. Should the lighting sit on a table, a desk, or on the floor? Accent lighting can be on a wall like a sconce, a pendant or hanging lamp, an arc lamp, or a special table lamp. Lamp structures are made of different metals and woods, glass and plastics. Lampshades also come in a variety of cloth, metal, paper, and plastic as well. So many design decisions! Using the web links, internet or other resource, research lamp types and locations. Find out about different lamp types and where they are used. Sketch and label five different lamp types. List their characteristics. Upload your lamp chart to the gallery!

Light engineers, architects and interior designers specify certain types of lamps to light spaces. The choice of lamps takes into consideration looks, style, form, and performance. Designers calculate light function using mathematical formulas to fit the amount of light needed in 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 lumens or measure of brightness. The amount of light that reaches the working surface ( your table, your book, the room, etc.) measures illumination, 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 for visual tasks 100 – 150
Warehouses, Homes, Theaters, Archives 150
Easy Office Work, Classes 250
Normal Office Work, Library 500
Remember, without light, natural or artificial, we cannot see!

• 24 / 7 means:
  • all day
  • all night
  • all day and all night
  • all day / all night / all week
• What two parts does a light have?
• A foot candle is:
  • a 12" candle
  • measure of light 1' from lit candle
• An incandescent bulb looks most like sunlight.
  • true
  • false
• Fluorescent bulbs are less efficient than incandescent bulbs:
  • true
  • false