● Ka ho sebelisa thepa e tsoetseng pele ea Jeremane le theknoloji ea ho roala, tekanyo ea ho nepahala e nepahetse, 'me motsoako oa likhalase tsa mahlaseli tsa letsatsi le filimi e mebala-bala e ka sefang khanya e phoroselang le khanya e khelohang, 'me pono e ba bonolo haholoanyane.
● Mefuta e mebala-bala e na le mefuta e mengata e fapaneng, e nang le li-index tse fapaneng, li-bend tse kholo le li-diameter tse kholo, tse mebala-bala, tse dailoeng, tse khonang ho finyella mefuta eohle ea batho ba roala likhalase tsa letsatsi.
● Lipatlisiso le nts'etsopele ea mekhoa e mengata: lilense tse fapaneng tsa mebala ea filimi e khanyang li na le mebala e fapaneng ea morao ho netefatsa liphello tse ntle tsa pono;
● Lense e manganga matheba 'me ha e che, e khona ho fetisa khanya hantle, 'me e sebetsa nako e telele.