Calculateur de Grossissement de Télescope Gratuit
Calculez le grossissement de votre télescope à partir de la focale et de l'oculaire.
Grossissement
48.0 ×
Magnification vs Objective Focal Length
Formule
## Telescope Magnification **M = f_objective / f_eyepiece** Swapping eyepieces changes magnification. The maximum useful magnification is roughly 2× per mm of aperture (e.g., 300× for a 150 mm telescope).
Exemple Résolu
1200 mm scope with a 25 mm eyepiece.
- 01M = 1200 / 25 = 48×
- 02Objects appear 48 times larger (linearly).
Questions Fréquentes
Is higher magnification always better?
No. Beyond the maximum useful magnification (about 2× per mm of aperture), the image becomes dim and blurry. Atmospheric turbulence also limits useful magnification.
What magnification do I need for planets?
Planets benefit from 100-250×. Jupiter's cloud bands and Saturn's rings are visible at 100×.
How does a Barlow lens work?
A Barlow is a diverging lens placed before the eyepiece that multiplies the effective focal length, typically by 2× or 3×, doubling or tripling magnification.