Lens Diffraction Calculator

Calculate the Airy disk diameter at each aperture to find the optimal f-stop before diffraction softens your images.

Results

Visualization

How It Works

Diffraction causes light to spread into an Airy disk pattern when passing through a small aperture. The disk diameter is 2.44 * wavelength * f-number. When the Airy disk becomes larger than your pixel pitch, diffraction visibly softens the image. Higher-megapixel sensors have smaller pixels and hit this limit at wider apertures. A 45MP full frame camera is diffraction-limited around f/6.5, while a 24MP camera can go to about f/9.