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SHEDDING THE LIGHT ON PROJECTION |
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What are lumens and how are they measured?
A lumen is a measurement of light. To get the lumen rating of a projector, it must be tested in a controlled environment so that a standard can be established. Some manufactures have their own standards but the most commonly used standard is dictated by ANSI (American National Standards Institute). The controlled environment used is interesting to note since the conditions are optimal for testing such equipment. · A fixed projection distance - each projector tested is set up the same distance from a screen. · No ambient light – the room the projector is tested in is completely dark, the only light source is that of the projector. · A new lamp or bulb is used – All lamps or bulbs loose their brightness over time and use. Inside of a bulb there is a chemical process that occurs when the chemicals are excited by an electrical current over time these chemicals “wear out”, causing them to put out less light. · An average of 9 readings taken with a light meter – the projection surface or screen is divided in to 9 equal parts a reading from the center of each section is taken and then averaged together.
It is important to know how a projector’s lumens are measured because most often these conditions can not be duplicated in a real world environment. By knowing the environment you will most often be using your projector in, will allow you to make a wise decision when purchasing a projector.
How many lumens should my projector be?
We are often asked, “What size or type of projector should I buy?” There really is no simple answer to this question, but with a little thought you can make your decision easier. |
