Optical Density Calculator

Formula

The formula to calculate the optical density (OD) is:

\[ OD = \log_{10} \left( \frac{I_0}{I} \right) \]

Where:

\( OD \) is the optical density.
\( I_0 \) is the incident optical intensity (optical intensity hitting the material).
\( I \) is the transmitted optical intensity (optical intensity transmitted by the material/film).

What is Optical Density?

Optical density is defined as the total optical attenuation per centimeter of material. Optical attenuation is the loss or amount of optical light that material retains as it travels over or through a medium.

Example Calculation

Consider an example where:

Incident Optical Intensity (I₀): 1000
Transmitted Optical Intensity (I): 100

Using the formula to calculate the optical density:

\[ OD = \log_{10} \left( \frac{1000}{100} \right) = \log_{10} (10) = 1 \]

This means that the optical density for this example is 1.