Which telescope is typically longer and heavier?

Which telescope is typically longer and heavier?

• A. Keplerian
• B. Galilean
• C. Both
• D. None

Answer: (A)

Keplerian telescopes use two converging lenses with their focal lengths spaced a distance roughly equal to the sum of those focal lengths. For a given magnification, this longer separation means a longer tube and larger lenses, which makes the instrument heavier. Galilean telescopes pair a converging objective with a diverging eyepiece, allowing the lenses to be placed closer together, producing a shorter, lighter tube for similar magnification. So, in terms of physical size and weight, the Keplerian design is typically longer and heavier.

Keplerian telescopes use two converging lenses with their focal lengths spaced a distance roughly equal to the sum of those focal lengths. For a given magnification, this longer separation means a longer tube and larger lenses, which makes the instrument heavier. Galilean telescopes pair a converging objective with a diverging eyepiece, allowing the lenses to be placed closer together, producing a shorter, lighter tube for similar magnification. So, in terms of physical size and weight, the Keplerian design is typically longer and heavier.