Nō te mea, e hāngai ana ngā kēti holo rima pūtake ki tētahi maha atu o ngā paihere whakamahere e mahi ai hei whakarite i ngā hiahia taapiri me ngā paihere tirotiro. Tuatahitia rawa, ko ngā tuhinga holo rima matihiko nā rātau i hanga te tirotiro ā-whatu noa, kia whakaae haere ngā paihere tirotiro i runga i ngā wāhi katoa, kāore he ahuatanga kēhei. Ko ngā āhuatanga optika kēi aua kēti ka hangaia ngā pūnaha mārama kēi, ka whai wawe iho te whakamahi, ka kitea he wāhanga whakahirahira, ka whakaritea he whakaiti i te whakapae i te whakapuru. Ka whai ngā kēti nei i te whanonga pai, ka ora i waenganui i ngā āhuatanga taiao katoa, ahakoa kua mau tonu te whakaaturanga ā-whatu me ngā paihere whakapiri. Ko te whanonga whaiaro pai kei raro i ēnei kēti, ka whakamana i a rātau ki te whakamahi i waenganui i ngā whenua, mai i ngā taonga taketake ki ngā tuhipoka whakahaere. Ko te horopaki porowhita ka whakapakari i te kiteaanga, ahakoa ka whakaiti i ngā huringa wāhi, ka whakamahia he whirinaki pai mo ngā hua me te iti o ngā wāhi. Ko te whakatinana he paihere iti tonu i roto i ngā paihere tirotiro kē, ka whakamana i te tiaki rangatiratanga whakahirahira ki te kore e taea ana te whakatipu i te moni nui. Ka taea te whakatika i ēnei kēti i runga i ngā raarangi kē, ngā pūmau rānei rānei, ka whakamahi i te hunga katoa ki te tiaki i te mana ingoa me te whakapakari i te tirotiro. Ko ō rātau paihere whakapuru e whai ana, ka kitea he toki whakapuru i runga i te kēti, ka whakamahi i tētahi rākau whakapuru tuatahi. Ko te paihere whakapiri matua ka whakamahi i te whakatipuranga tino nuinga ki ngā wāhi katoa, kāore e mate ana i te raraunga i runga i te raraunga matua. Ka whai hoki ēnei kēti i te whakapakari i te whakatipuranga, ka mau tonu te pai i roto i ngā pūrongo iti rānei, ngā pūrongo nui rānei. Ko te iti o ngā huringa tirotiro me te roa o te wā ka whakamahi i a rātau hei whakamahi pai mo ngā paihere whakarite mō te wā e whai ake nei.