Detailed Description Advances in low-dispersion optical glass and exotic anti-reflection coatings, along with the latest in computer-aided manufacturing are combined to produce lenses of unprecedented quality. Rather than raising the cost of Opteka filters however, these advanced materials and techniques allow more efficient and economical production. The results are lenses of remarkable quality and durability at remarkably affordable prices. Your pictures are only as good as the glass in your lens. Nothing changes the way you see the world like High Definition II and no company does High Definition II like Opteka. Opteka's glass optics define High Definition. Change the way you view the world. Enjoy outstanding detail, enjoy enhanced clarity, enjoy Opteka.