Calculateur de Magnitude Limite — Formule
## Limiting Magnitude of a Telescope
**m_lim ≈ 2 + 5 log10(D)** (D in mm)
This empirical formula assumes a dark sky, normal magnification, and good optics. The naked eye (7 mm pupil) reaches about +6.0.
Each doubling of aperture adds about 1.5 magnitudes (3.6× fainter stars).
**m_lim ≈ 2 + 5 log10(D)** (D in mm)
This empirical formula assumes a dark sky, normal magnification, and good optics. The naked eye (7 mm pupil) reaches about +6.0.
Each doubling of aperture adds about 1.5 magnitudes (3.6× fainter stars).
Exemple Résolu
A 200 mm (8-inch) telescope.
- m_lim = 2 + 5 × log10(200)
- = 2 + 5 × 2.301 = 2 + 11.505 = 13.5
- Can see stars down to about magnitude 13.5.
- Gain over eye: 5 × log10(200/7) = 5 × 1.456 = 7.3 mag