From the June 2008 issue

Binocular 101: Prisms

What binoculars are best for you?
By | Published: June 23, 2008 | Last updated on May 18, 2023

Gemini Sparkle

Key Takeaways:

  • Reader inquiries frequently concern the optimal binocular type for astronomical observation.
  • Two primary binocular prism designs are distinguished: Porro prism and roof prism.
  • Porro prism binoculars are characterized by their outwardly angled, zigzag-shaped barrels.
  • Roof prism binoculars possess a streamlined, straight barrel design.
Many readers have written to ask which binoculars are best for stargazing: those with Porro prisms or those with roof prisms. They’re easy to tell apart. Porro-prism binoculars have zigzag-shaped barrels, while roof-prism models have sleek, straight barrels.