Diffraction limit

The calculator calculates the size of the circle of confusion and assesses the susceptibility of the system to the diffraction limit. Optional fields are marked dark gray and allow you to specify your own circle of confusion (CC).

This online calculator considers the system to have reached the diffraction limit when the diameter of the Airy disk exceeds the diameter of the circle of confusion. For a detailed explanation of each input parameter, refer to the advanced DOF calculator. The ability to equate CC to twice the pixel size gives you an idea of when diffraction becomes noticeable when viewing a digital image on a computer screen at 100%. It should be understood that «double pixel» is the absolute limit, and in reality, there is a smooth transition between imperceptible and noticeable diffraction at 100%. In reality, the results will also depend on the lens used, so this limit is achievable only for the sharpest lenses.