BK7 vs K9 Optical Glass: Which is Best for Optical Domes?

BK7 vs K9 Optical Glass: Which is Best for Optical Domes?

Summary

Wondering which optical glass is best for your domes? Felix Glass compares BK7 and K9 glass, covering their differences, applications, and how to choose the right material for your project. Get free quote now!

BK7 vs K9 Optical Glass: Which is Best for Optical Domes?
Felix Glass explains the key differences between BK7 and K9 optical glass for custom optical domes. Both are high‑quality optical glasses, but they have distinct refractive indexes, durability levels, and cost structures.
 
BK7 glass has a lower refractive index (~1.51) and excellent transmittance across the visible spectrum. It is widely used for CCTV camera domes, underwater camera domes, and general optical applications. BK7 is cost‑effective, easy to process, and suitable for most standard‑performance requirements.
 
K9 glass has a higher refractive index (~1.52) and better optical clarity, making it a preferred choice for high‑precision applications such as aerospace domes, medical imaging lenses, and high‑end security systems. K9 is more stable under temperature changes and can deliver sharper imaging.
 
In summary:
 
- Choose BK7 for cost‑effective, standard optical domes
- Choose K9 for higher precision, clarity, and demanding applications
 
At Felix Glass, we provide custom sizing, AR/AF/AG coating, and full OEM/ODM support for both BK7 and K9 optical domes. Contact us for a free quote.