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Photography & video

Diffraction Airy Disk Calculator

Estimate the first-dark-ring diameter of a diffraction pattern at the image plane.

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Photo & video desk
Photo & video desk

Match the sensor, lens and output settings to your equipment.

See the method

Set up your shot

Runs on your device

Your camera calculation

Your result

Let’s calculate.

Use the Calculate button to see your result.

Review the method below for assumptions and conventions.

How to use this tool

  1. Enter wavelength, f-number.
  2. Select Calculate to view the result.
  3. Check the method and assumptions below before using the result.

The method, explained

Airy disk diameter = 2.44 × wavelength × f-number.

A WORKED EXAMPLE

Using wavelength = 550 nm, f-number = 8, the result is 10.736 µm. Change these example inputs to match your task; use the method above to check each step.

Understanding your result

Ideal circular aperture in the paraxial limit. Aberrations, sensor sampling and demosaicing also affect visible detail.

What to keep in mind

Ideal circular aperture in the paraxial limit. Aberrations, sensor sampling and demosaicing also affect visible detail. An ideal geometric or exposure estimate. Lens behavior, stabilization, sensor crop and scene conditions may change practical results.

Common questions

How do I use this diffraction airy disk calculator?

Estimate the first-dark-ring diameter of a diffraction pattern at the image plane. Enter wavelength in nm, f-number. The starting example is editable; use values for the same system or project.

Which assumptions affect this result?

Ideal circular aperture in the paraxial limit. Aberrations, sensor sampling and demosaicing also affect visible detail.

Methodology maintained by ClarityKit. How these tools are built and checked.