illuminance

Illuminance is the amount of light incident on a surface.

However, the illuminance level is not the only factor governing visibility.

At perigee it would add more than ten percent to the planet's illuminance.

Here are some examples of the illuminance provided under various conditions:

Illuminance was formerly often called brightness, but this leads to confusion with other uses of the word.

This means that a light source must be four times as bright to produce the same illuminance at an object twice as far away.

Point in the light field (lighted area) where illuminance reaches maximum lux intensity.

Therefore, it can be argued that the most important purpose of task lighting in the office is not increasing illuminance, but improving contrast.

The exposure time is the same for all elements, but the image illuminance varies with the luminance of each subject element.

Most plants will survive illuminance 10 times lower than listed below but will not grow as well or bloom.

Fundamentally, the algorithm is integrating over all the illuminance arriving to a single point on the surface of an object.

Illuminance is a measure of how much luminous flux is spread over a given area.

When the spot is not visible from either side, the illuminance from the two sides is equal.

A poorly placed lamp may render text illegible, regardless of illuminance level.

This technique is similar to using an incident meter, as it depends on the illuminance but not the reflectivity of the subject.

It is commonly used in lighting applications that require minimal glare and uniform general illuminance levels.

Bright, sharp caustics; radiance scales by the density of illuminance in space.

In photometry, illuminance is the total luminous flux incident on a surface, per unit area.

In astronomy, apparent magnitude is a measure of the illuminance of a star on the Earth's atmosphere.

The sum of the three components gives the illuminance level (lux) at the point considered:

The table at the end of the article used units of illuminance and the symbol , as noted above.

Exposure is a combination of the length of time and the illuminance at the photosensitive material.

Illuminance is measured with a flat receptor.

The formal relationship of EV to luminance or illuminance has limitations.

This illuminance is then reduced by a surface reflectance function to determine how much of it will go towards the viewpoint camera.