Telescopes & instruments · M = f_telescope / f_eyepiece

Telescope Magnification

The magnification of a telescope–eyepiece pair — the ratio of their focal lengths. Useful magnification is capped by the aperture and the atmosphere, not by the eyepiece alone.

Telescope focal length (mm)Eyepiece focal length (mm)

Magnification100×

Formula: M = f_telescope / f_eyepiece

Worked example

With the default inputs, telescope magnification evaluates to 100 × — 1000 mm / 10 mm → 100×. The validator recomputes this against the known value on every build, so the formula is checked, not asserted.

Highlights

›1000 / 10 mm → 100×

Angular Resolution (Rayleigh)

Knowledge connections

Associated withAngular Resolution (Rayleigh)

Sources

Facts on this topic will be cited from these primary and reference sources.

NASANational Aeronautics and Space Administration
Mission data, planetary science, space telescopes, and public-domain imagery.
Most NASA-produced imagery is in the public domain; individual items are checked for usage terms before publication.

Loading…

Telescope Magnification

Worked example

Highlights

The physics behind it

Knowledge connections

Sources

Telescope Magnification

Worked example

Highlights

The physics behind it

Knowledge connections

Sources