Aperture

Aperture is the diameter of the main lens or mirror of a telescope in inches or cm.

The larger the aperture, the greater the light grasp and resolving power. Optical instruments with a larger aperture can therfore see fainter objects and separate more closely spaced objects.

The effective aperture of a reflecting telescope is reduced by the secondary mirror. Size for size therefore, a refracting telescope is better.

Comments are closed.

Switch to our mobile site