Dawes' Limit Calculator
Calculate the maximum theoretical resolving power of a telescope based on its aperture.
Common sizes: 70mm, 114mm, 150mm, 200mm, 254mm.
arcseconds
What is Dawes' Limit?
Dawes' Limit is a formula to estimate the maximum resolving power of a telescope. It specifically refers to the ability to distinguish two close stars as separate objects.
The Importance of Aperture
In astronomy, aperture (the diameter of the main lens or mirror) is king. The larger the aperture, the smaller the diffraction pattern of a star, allowing you to see finer details on planets or split tighter double stars.
Frequently Asked Questions (FAQ)
Why can't I see this level of detail?
Atmospheric turbulence (often called "seeing") usually limits resolution to about 1 arcsecond, regardless of telescope size.
What is Rayleigh's Criterion?
Rayleigh's Criterion is a more scientifically rigorous way to define resolution based on the diffraction of light. Dawes' Limit is an empirical rule often used by visual observers.