Diffraction Limit Calculator

Formula

The formula to calculate the Diffraction Limit (DL) is:

\[ \text{DL} = 1.22 \times \frac{w}{d} \]

Where:

\( \text{DL} \) is the Diffraction Limit (radians)
\( w \) is the Wavelength of the Light (cm)
\( d \) is the Diameter of the Telescope (cm)

Diffraction Limit Definition

A diffraction limit is the minimum angular separation that a telescope or microscope can distinguish between. It is a measure of the maximum limit of resolution seen by a telescope.

Why is the Diffraction Limit Important?

The diffraction limit is important because it defines the limit of the resolving power of a telescope. Decreasing the diffraction limit allows a telescope to distinguish between objects that are very far away but relatively close together.

A diffraction-limited aperture is an aperture whose performance is capped by the size of the aperture. It has reached its maximum resolution for its current size.

Example Calculation

Let's consider an example:

Wavelength of Light (w): 0.00055 cm (which is 550 nm, a common wavelength for visible light)
Diameter of Telescope (d): 10 cm

Using the formula to calculate the Diffraction Limit:

\[ \text{DL} = 1.22 \times \frac{0.00055}{10} = 0.0000671 \, \text{radians} \]

This demonstrates that with a wavelength of 0.00055 cm and a telescope diameter of 10 cm, the diffraction limit would be approximately 0.0000671 radians.