1. What is a Lens Diffraction Calculator?

Definition: This calculator estimates 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:

• \( θ \) — Diffraction angle (radians)
• \( λ \) — Wavelength of light (meters)
• \( D \) — Diameter of the aperture (meters)
• 1.22 — Constant derived from the first zero of the Bessel function

Explanation: The formula describes the angular size of the Airy disk, which is the smallest point to which a beam of light can be focused.

3. Importance of Diffraction Calculation

Details: Understanding diffraction helps in determining the resolution limits of optical systems and choosing appropriate aperture sizes for desired image quality.

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 about 400nm (violet) to 700nm (red), with 550nm (green) often used as a standard reference.

Q2: How does aperture size affect diffraction?
A: Smaller apertures produce more noticeable diffraction effects, leading to softer images at very small apertures.

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

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

Q5: Does this apply to all types of light?
A: Yes, the principle applies to all electromagnetic waves, though the effects are most noticeable with coherent light sources.