1. What is a Lens Diffraction Calculator?

Definition: This calculator determines the diffraction angle of light passing through a circular aperture using the Rayleigh criterion.

Purpose: It helps photographers, astronomers, and optical engineers understand the resolution limits of their optical systems.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( \theta \) — Diffraction angle (radians)
• \( \lambda \) — Wavelength of light (meters)
• \( D \) — Diameter of the aperture (meters)

Explanation: The formula describes the angular size of the Airy disk, the diffraction pattern produced when light passes through a circular aperture.

3. Importance of Diffraction Calculation

Details: Understanding diffraction helps in designing optical systems with optimal resolution and in predicting image quality limitations.

4. Using the Calculator

Tips: Enter the wavelength of light (typically 550nm or 0.00000055m for visible light) and the aperture diameter. Both values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What is the 1.22 factor in the formula?
A: This is the first zero of the first-order Bessel function, representing the first dark ring in the Airy pattern.

Q2: How does aperture size affect diffraction?
A: Smaller apertures produce more noticeable diffraction effects, leading to larger Airy disks and reduced resolution.

Q3: What's a typical wavelength for visible light?
A: The visible spectrum ranges from about 400nm (violet) to 700nm (red), with 550nm (green-yellow) often used as a standard.

Q4: How do I convert radians to degrees?
A: Multiply radians by (180/π) ≈ 57.2958 to get degrees.

Q5: Does this apply to all lens shapes?
A: The formula is specifically for circular apertures. Other shapes have different diffraction patterns.