Magnification
Also called: power, ×.
How much bigger a telescope makes things look: its focal length divided by the eyepiece's focal length.
Magnification is the least important number on a telescope box. Too little and small objects stay tiny; too much and the image turns dim, soft and shaky. Each target has a sweet spot — set by the exit pupil it needs, how big it is, and the seeing.
Rough guide: low power (4–6 mm exit pupil) for big clusters and nebulae, medium (2–3 mm) for galaxies and most deep-sky objects, high (0.7–1.2 mm) for planets, the Moon and close doubles.
In AstroPilot
Object pages pick the eyepiece from your kit that gives the best power for each target, and why.