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 limitations of lens resolution due to diffraction.

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)
• 1.22 — Rayleigh criterion constant for circular apertures

Explanation: The formula calculates the angular size of the Airy disk, which represents the smallest resolvable detail due to diffraction.

3. Importance of Diffraction Calculation

Details: Understanding diffraction helps optimize lens performance, determine resolution limits, and balance aperture settings in photography.

4. Using the Calculator

Tips: Enter the wavelength of light (default 550nm = 0.00000055m for green light) and aperture diameter. All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What's a typical wavelength for visible light?
A: Visible light ranges from ~400nm (violet) to 700nm (red), with 550nm (green) often used as a standard reference.

Q2: How does aperture size affect diffraction?
A: Smaller apertures (larger f-numbers) produce more noticeable diffraction effects, reducing image sharpness.

Q3: What is the Rayleigh criterion?
A: It defines when two point sources are just resolvable - when the center of one Airy disk falls on the first minimum of the other.

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

Q5: What practical applications does this have?
A: Useful for telescope design, microscope resolution limits, and determining optimal camera apertures for sharpness.