Calcium Fluoride (CaF₂)
Ruwan tabarau na Plano-Convex

Ruwan tabarau na Plano-convex suna ba da ƙarancin juzu'i lokacin da aka mayar da hankali kan iyaka (lokacin da abin da aka zana ya yi nisa kuma rabon haɗin gwiwa ya yi girma). Saboda haka su ne abin tafi-da-gidanka a cikin kyamarori da na'urorin hangen nesa. Ana samun mafi girman inganci lokacin da saman plano ya fuskanci jirgin da ake so, a wasu kalmomi, saman mai lanƙwasa yana fuskantar katakon da ya haɗu. Ruwan tabarau na Plano convex kyakkyawan zaɓi ne don haɗuwar haske ko don mayar da hankali kan aikace-aikace ta amfani da hasken monochromatic, a cikin masana'antu kamar masana'antu, magunguna, robotics, ko tsaro. Zabi ne na tattalin arziki don buƙatar aikace-aikacen saboda suna da sauƙin ƙirƙira. A matsayinka na babban yatsan hannu, ruwan tabarau na plano-convex suna aiki da kyau lokacin da abu da hoton suke a cikakkiyar ma'auni na haɗin gwiwa> 5: 1 ko <1:5, don haka an rage ɓarnawar yanayi, coma da murdiya. Lokacin da cikakken girman da ake so ya kasance tsakanin waɗannan dabi'u biyu, ruwan tabarau Bi-convex yawanci sun fi dacewa.