3D tool

Telescope Simulator

A three-dimensional telescope on a mount, paired with a simulated eyepiece view. Adjust aperture, focal length, eyepiece, Barlow and target, then watch the field of view render with the correct relative object size, brightness and — at high power — diffraction rings.

Simulated values for education. Orbits and geometry are simplified; results are approximations, not an ephemeris and not a substitute for your equipment manual.

Drag to orbit the model · scroll to zoom

The 3D model needs WebGL. The eyepiece field above and every figure on the right are computed the same way without it.

Optical train

Change anything; the field updates immediately.

Aperture (mm) 150

Focal length (mm) 1200

Eyepiece (mm) 10

Barlow

Target

Focus sharp → soft

Seeing (atmospheric turbulence)

Computed

Magnification	—
Exit pupil	—
True field	—
Limiting magnitude	—
Resolution	—
Effective focal ratio	—
Maximum useful	—

Suggested eyepieces

Controls

Optics — aperture, focal length, eyepiece focal length, Barlow factor
Target — Moon, Jupiter, Saturn, Mars, Orion Nebula, Andromeda Galaxy, Pleiades
Focus — a focus slider that sharpens and softens the simulated field
Seeing — atmospheric turbulence from excellent to poor

What it produces

Magnification — telescope focal length ÷ eyepiece focal length, × Barlow
Exit pupil — aperture ÷ magnification
True field — apparent field ÷ magnification
Limiting magnitude — from aperture and exit pupil
Resolution — Dawes limit for the aperture, in arcseconds
Eyepiece suggestions — combinations that reach low, medium and high power

Without WebGL the simulator shows a two-dimensional telescope diagram, the same eyepiece field rendering on canvas, and the same set of computed figures and recommendations.

Stargazer's Atlas is an independent educational reference. Simulations model approximate behaviour and do not predict what your equipment will show.