11. It is also used in making optical glasses and lenses. 12. Budget models may not use optical glass at all, and some really cheap ones use plastics. 13. The new Jena optical glass also opened up the possibility of increased performance of photographic lenses. 14. Multi-element precision ground optical glass with anti-reflection coatings. 15. They include a melted telescope mirror and a piece of melted optical glass ( flint ). 16. Optical wedges and reflections from uncoated optical glass surfaces are used to attenuate high power laser beams. 17. AN-6530 lenses are ground and polished optical glass , approximately of an inch ( 2.4 mm ) thick. 18. It can be argued that casting of this mirror launched the optical glass industry in the United States. 19. The first attempt to fabricate the primary mirror was made by the Lytkarino Optical Glass Factory, near Moscow. 20. The difficulties of fabricating two disks of optical glass required to make a large achromatic lens were formidable.
