Angular Resolution Calculator

Find the smallest angle a lens or telescope can resolve.

Angular resolution (rad) 0

Angular resolution (arcsec) 1.384

Formula: θ = 1.22·λ ÷ D

Step-by-step with your numbers:

1. Values used:

2. Wavelength = 550 nm

3. Aperture diameter = 100

5. Angular resolution = 0rad

6. Angular resolution = 1.384arcsec

Did we solve your problem today?

Diffraction sets the finest detail an optical instrument can distinguish.

The math behind it

The Rayleigh criterion gives θ = 1.22·λ ÷ D. A larger aperture resolves finer detail.

550 nm light, 100 mm aperture → ≈ 6.7 µrad (1.4 arcsec).

Why bigger telescopes?

A larger aperture lowers θ, resolving finer detail and gathering more light.