Light Intensity Calculator

Formula

The formula to calculate Light Intensity (I) is:

\[ I = \frac{n \times f \times h}{A \times t} \]

Where:

\( I \) is the Light Intensity (candela, cd)
\( n \) is the Number of Photons
\( f \) is the Frequency (Hz)
\( h \) is Planck's Constant (J·s)
\( A \) is the Incident Area (m²)
\( t \) is the Time (seconds)

What is Light Intensity?

Light intensity, or luminous intensity, is a measure of the power emitted by a light source in a certain direction. This measurement considers the wavelength and the amount of light that spreads over a given area. In photometry, light intensity is a crucial concept, and it is often measured in candelas (cd). Understanding light intensity helps in various fields, including photography, lighting design, and optical engineering.

Example Calculation

Let's consider an example:

Number of Photons (n): 1e20
Frequency (f): 5e14 Hz
Planck's Constant (h): 6.62607015e-34 J·s
Incident Area (A): 1 m²
Time (t): 2 seconds

Using the formula to calculate Light Intensity:

\[ I = \frac{1e20 \times 5e14 \times 6.62607015e-34}{1 \times 2} = \frac{3.313035075e1}{2} = 1.66 \, \text{cd} \]

This means that the light intensity is approximately 1.66 candela.