In the formula T = LA, what does 'L' stand for?

In the formula T = LA, the letter 'L' represents luminance. Luminance is a measure of the amount of light that is emitted, transmitted, or reflected from a surface in a given direction and is typically expressed in candelas per square meter (cd/m²). It is a crucial factor in visual perception because it affects how we perceive brightness and contrast in our environment.

Understanding luminance is essential in various applications, such as adjusting lighting in visual displays, working with photography to achieve the desired exposure, and assessing visual conditions in clinical optometry. In this formula, luminance serves as a foundational element for determining the overall perceived brightness (T) of a visual stimulus when combined with the viewing area (A). This relationship highlights the importance of both the light intensity that reaches the observer and the area over which that light is distributed in visual perception.