Optical refracting telescopes
A refracting telescope uses lenses to focus the incoming light rays.
Most modern optical telescopes are
reflectors rather than refractors, because:
- Lenses suffer from chromatic aberration. Light waves
of different wavelengths are bent by different amounts as they
pass through the glass, so that each wavelength has a slightly
different focus than the others.
- It is harder to make and support a large lens than a