PDA

View Full Version : picture books


The Lighting Geek
11-06-2010, 06:11 PM
If you would like to know about the picture books I spoke of in earlier posts, please PM me.

ajslands
11-06-2010, 06:13 PM
I have a question, what is the measurement foot candles used for?
Posted via Mobile Device

The Lighting Geek
11-06-2010, 06:40 PM
It is the measurement of light that falls onto a surface. Typically it is used to maintain a standard of light for a particular task, such as a regulation tennis court or a kitchen task lighting. It is the amount of light in a 1 foot circle produced by a candle in the middle. That is how I understand it, I'm sure someone will correct me if I am wrong.

In landscape lighting it would be the measurement of the light that lands on a sidewalk for example. It can be referenced as less than 1 foot candle as well, .5 FC.

OSHA has standards for work spaces for things such as, offices 30 FC., hallways 5 FC, etc.

ajslands
11-07-2010, 09:54 AM
How do you meassure how much light something produces?
Posted via Mobile Device

INTEGRA Bespoke Lighting
11-07-2010, 11:09 AM
You use a Light Meter. Or you refer to the IES photometry reports that come with most quality fixtures, lamps, etc.

steveparrott
11-07-2010, 11:12 AM
It is the measurement of light that falls onto a surface. Typically it is used to maintain a standard of light for a particular task, such as a regulation tennis court or a kitchen task lighting. It is the amount of light in a 1 foot circle produced by a candle in the middle. That is how I understand it, I'm sure someone will correct me if I am wrong.

In landscape lighting it would be the measurement of the light that lands on a sidewalk for example. It can be referenced as less than 1 foot candle as well, .5 FC.

OSHA has standards for work spaces for things such as, offices 30 FC., hallways 5 FC, etc.

Close, but it is the amount of light that falls on the interior surface of a 1 ft. radius sphere with a light source of 1 candela in the center. A more useful description is "the number of lumens that fall on one square foot of surface".

For example, if you have a light source of 10 lumens and all the light were projected onto a surface of one square foot then you would have an illuminance of 10 foot candles.

steveparrott
11-07-2010, 11:30 AM
A useful illustration of basic photometric concepts. For explanation of some of the most common terms, see the article: Lighting Terminology for the Landscape Lighting Designer (http://www.cast-lighting.com/search/1/display-document/128).

The Lighting Geek
11-07-2010, 11:48 AM
Thanks Steve for that diagram, i'm sure it will help everyone better understand the terminology of lighting.