Focal Length Explained

Focal length describes the distance that light travels inside a telescope before reaching focus. It's measured in millimetres (mm) and influences both magnification and the field of view.

Short Focal Length

Short focal length telescopes provide:

  • Wide fields of view

  • Lower magnification

  • Excellent views of large nebulae and star clusters

  • Great performance for astrophotography

Long Focal Length

Long focal length telescopes offer:

  • Higher magnification

  • Narrower fields of view

  • Excellent planetary observing

  • Detailed lunar views

Is Longer Better?

Not necessarily.

A shorter focal length telescope may be perfect for photographing the Milky Way, while a longer focal length telescope is better suited to observing Saturn's rings.

The ideal focal length depends on what you want to observe.

Our Advice

Rather than looking at focal length in isolation, consider it alongside aperture and mount quality. Together they determine how your telescope performs across different types of observing.