FAQ:What's the differences between Radiometric Units and Photometric Units?

Thread starter s7k22
Start date May 16, 2007
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In summary, radiometric units measure the total amount of energy emitted by a light source, while photometric units measure the perceived brightness of the light by the human eye. Some common examples of radiometric units are watts, joules, and electron volts, while photometric units include lux, candela, and lumens. These units are related through a conversion factor called luminous efficiency, which takes into account the sensitivity of the human eye. Photometric units are more commonly used in everyday life, as they are based on human perception of light. Other differences between radiometric and photometric units include their absolute vs relative nature and their range of measurement (all electromagnetic radiation vs visible light).

May 16, 2007

s7k22

What's the differences between Radiometric Units and Photometric Units?

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May 16, 2007

Hootenanny

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FYI: http://www.optics.arizona.edu/Palmer/rpfaq/rpfaq.htm

Last edited by a moderator: May 2, 2017

May 16, 2007

s7k22

Thanks a lot!

FAQ: FAQ:What's the differences between Radiometric Units and Photometric Units?

What is the main difference between radiometric units and photometric units?

Radiometric units are used to measure the total amount of energy emitted by a light source, while photometric units measure the perceived brightness of the light by the human eye.

Can you provide examples of radiometric and photometric units?

Some common radiometric units include watts, joules, and electron volts. Photometric units include lux, candela, and lumens.

How are radiometric and photometric units related?

Radiometric and photometric units are related through a conversion factor known as luminous efficiency. This factor takes into account the sensitivity of the human eye to different wavelengths of light and allows for the conversion between radiometric and photometric units.

Which units are more commonly used in everyday life?

Photometric units are more commonly used in everyday life because they are based on human perception of light. For example, we use lumens to measure the brightness of light bulbs and lux to measure the brightness of our surroundings.

Are there any other differences between radiometric and photometric units?

Yes, there are a few other differences between these units. For one, radiometric units are absolute and do not depend on distance or angle, while photometric units are relative and can change with distance and angle. Additionally, radiometric units are used to measure all types of electromagnetic radiation, while photometric units are specific to visible light.