Visibility

With Visibility tab, you can evaluate the visibility of an object having an angular size superior to 4 degrees.

Note: The object can be as an example a reflection into a windshield.

Note: This evaluation is partly based on the work done by Blackwell. References are Blackwell, H.R. Contrast threshold of the human eye, Journal of the optical society of America 1946, 36, 624-643.

Previous Adaptation Luminance

In Previous adaptation luminance box, you can type the luminance (L0) value at which the observer is adapted before seeing the current object. Value is in cd/m².

Observation Time

In Observation time box, you can type the time during which the observer has been adapted to the luminance L0. Value is in seconds.

Observer Age

In Observer age box, you can type the age of the observer in years.

Background Luminance

In Background luminance box, you can type the luminance value of the background around the target in cd/m².

Note: If needed, you can click

to select a pixel in the map. If needed, you can click

to clear the previous selection.

Target Luminance

In Target luminance box, you can type the luminance value of the object for which you want to analyze visibility in cd/m².

Note: If needed, you can click

to select a pixel in the map. If needed, you can click

to clear the previous selection.

Curve Options

In Curve options group box, you can select the option to display the visibility diagram with delta luminance in cd/m² in function of the background luminance in cd/m².

Note: Delta luminance is equal to the difference between background luminance and target luminance.

Note: Visibility state box gives information if the target is visible.