Real Time Analytics
 Planetech Logo              LED Brights, the future of Lighting.




LED Downlights
8" LED downlight
6" LED downlight
5" LED downlight
4" LED downlight
3" LED downlight
LED Spot/Flood Lights
PAR38 Flood
LP 12 Spot
LP 5 Spot
LED Downlights Decor Style  
6" Ceiling Light
6" Wall Light
6" Drop Light
2" LED swivel lights
About Us
Contact Us







Home Products Why LED Lighting Installations Technology About Us Contact Us  

   Understanding Lighting


LED Electrical Power Savings


LED lighting offers the most efficient source of light available with long life and excellent quality of light.   As it looks now, LED lighting will be the dominant source of all future lighting.   It will save very significant energy for the world and provide better lighting quality for us all.

  • 80% compared to incandescent bulbs
  • 50% compared to compact fluorescent lamps
  • 60% compared to fluorescent lamp.
  • 75% compared to halogen lamp.
  • 80% compared to mercury-vapor lamp.
  • 65% compared to high pressure sodium lamp.

Color Temperature


Description:  The Color Temperature of lighting indicates how the light will appear to the human eye when looking directly at the illuminated bulb. Color temperature is measured in Kelvin (K) degrees as apposed to Fahrenheit Celsius due to its common use in thermodynamics.   The hotter an item is the more the light output changes from red to white to blue white to blue. 

Color Selection:   A light bulb that produces light perceived as yellowish white will have a color temperature of around 2700K. As the color temperature increases to 3000K - 3500K, the color of the light appears less yellow and more white. When the color temperature is 5000K or higher the light produced appears bluish white. The color temperature of daylight varies, but is often in the 5000K to 7000K range.

LED Lighting History:    Early LED lighting was often available at only at high Color Temperatures....providing a very Blueish White light.   This made the LEDs appear to be very bright, but, also caused a lot of glare when assembled in arrays of LEDs.   LED lighting is now available at the full range of color temperatures.   So, it is now possible to provide lighting which closely matches Incandescent lighting which we are familiar and comfortable with. 

Glare:   Lighting which is at a lower Color Temperature will produce less glare than higher temperatures.  Downlighting with high lumen output at high Color temperatures can produce an uncomfortable amount of glare.

Comfort:  Lower temperatures provide a more relaxed and comfortable setting for living rooms, dining rooms, great rooms, dens, lobbies, evening restaurants, etc.   In contrast, higher temperatures may be more desireable for active areas, kitchens, bathrooms, day restaurants, offices and factories.


Incandescent Bulb Color Temperatures for Comparison

  Incandescent Watts   Color Temperature      
150 2850
  100   2850      
75 2850
60 2650
40 2500

Color Rendering Index (CRI)


CRI measures the ability of a light source to render a variety of colors compared to an incandescent light source.   Measurement is from 0 to 100; 100 being equal to an incandescent light bulb.  Variations of 3 or 4 points is not that significant as it is difficult to perceive the difference with the naked eye.    The Chart to right shows colors that are used to make up the index.  Appearance under daylight may give different colors than an incandescent reference bulb.

But, this comparison must be made with a lamp of the same Color Temperature to be valid.   Also, Incandescent bulbs have difficulty with rendering some colors such as dark Navy Blue compared with Black.

Again, these measurements are subjective due to the huge variety of color hue combinations and importance of particular colors to the viewer.    Researchers are looking for a better, more accurate measurement method.

The CRI of Fluorescent lamps is notorious for low CRI readings. This is often the reason for people generally not liking Flourescent lighting without understanding why.   It is primarily due to the limited light spectrum output of these lamp types. However, the CRI can be faked to create a high number by adjusting the phosphors to influence the CRI readings.   This is one of the problems of using the CRI index.

Subjectiive Comparison Test

Designers put their hand in front of the light to see the effect on their skin. This is often a good, though subjective, measure of the quality of a light source.   This should be compared to light on the skin from an incandescent bulb.   An alternative is to choose a selection of colors that are important to the user.


Appearance under daylight



Light greyish red


Dark greyish yellow


Strong yellow green


Moderate yellowish green


Light bluish green


Light blue


Light violet


Light reddish purple


Strong red


Strong yellow


Strong green


Strong blue


Light yellowish pink


Moderate olive green (leaf)


General Area Lighting Efficiency


Downlight Spot Downlight housing with Spot or Flood Light. 

 Brights LED Downlight


Downlight housings with regular bulbs, spot lights or flood lights installed are not efficient for general area lighting.   Note in the photo that much of the light will be focused directly down and not spreading out.   Such lights are good for focused lighting on specific objects or areas.   Installation of standard incandescent or compact fluorescent bulbs in a downlight housing is very inefficient and usually inappropriate. 

A downlight housing with our LED Downlights installed will provide a well distributed light, very efficient, for general lighting of the area.

Home Products Why LED Lighting Installations Technology About Us Contact Us  

© 2009 Planetech International, LLC   All rights reserved.