Ka taea te whakatika i te tirohanga tata me te tirohanga tawhiti mā te whakamahi i ngā karaihe mōhiti me ngā karaihe whakapā . Ka piri ngā karaihe mōhiti ki ngā karaihe, ko ngā karaihe whakapā ia ka piri ki te kanohi. Kei te tawhiti motuhake ngā karaihe mai i te kanohi, ko ngā karaihe whakapā ia ka piri ki te kanohi, nō reira he iti noa te tawhiti i waenganui i te karaihe whakapā me te kanohi.
E whakamārama ana tēnei tuhinga i ngā tauira o ngā raruraru e pā ana ki te hunga kite tata me te hunga kite tawhiti, ngā momo karāhe e whakamahia ana hei whakatika i te tirohanga, ō rātou roa arotahi, me ō rātou kaha. E arotahi ana tēnei tuhinga ki te whakamahinga o ngā karāhe whakapā hei whakatika i ngā kanohi kite tata me te hunga kite tawhiti.
Te Tirohanga Tata me ngā Arotahi Kōpiko
Ko te tawhiti rawa atu ka kitea mārama e te tangata kite tata, e te tangata whanoke rānei, he 50 cm. Kia mārama ai te kite a te tangata kite tata i ngā mea i te tawhiti mutunga kore, whakatauhia (a) te momo karāhe arotahi e whakamahia ana, (b) te roa o te arotahi o te karāhe arotahi me te momo karāhe arotahi, (c) te kaha, te mana rānei o te karāhe arotahi.
He tino tata ngā karāhe whakapā ki te kanohi, nō reira kaua e aro ki te tawhiti i waenganui i te karāhe me te kanohi. Ko te tawhiti i waenganui i te mea me te ahua me te karāhe whakapā e kiia ana he rite tonu ki te tawhiti i waenganui i te mea me te ahua me te kanohi.
Kōrero
(a) Momo karaihe i whakamahia
Mō te kaupapa te tirohanga tata Kua whakamāramahia ko ngā karāhe arotahi e whakamahia ana hei whakataurite i te tirohanga tata o ngā kanohi ko ngā karāhe arotahi kōpiko, ko ngā karāhe arotahi wehewehe, ko ngā karāhe arotahi kino rānei.
(B) Roa arotahi o te arotahi
Ko te mea e kitea ana e te kanohi tata mā te karu arotahi kei te mutunga kore, nō reira me hanga e te karu arotahi he ahua i te tawhiti o te 50 cm ki mua i te karu arotahi. Kei mua te ahua i te karu arotahi, nō reira he mariko te ahua (whakatairitehia te whakamārama i roto i te kaupapa whakaahua karaihe kōpiko)
E mōhiotia ana :
Te tawhiti o te mea (s) = te mutunga kore
Te tawhiti o te ahua (s') = -50 cm (kino nā te mea he mariko te ahua)
I pātaihia Roa (f)
Whakautu :
1/h = 1/h + 1/h'
1/f = 1/~ + (- 1/50)
1/f = 0 – 1/50
1/f = – 1/50
f = – 50/1 henimita = -50 henimita = -0,5 mita.
Ko te roa arotahi kino ko te arotahi e whakamahia ana he karāhe kōpiko ranei arotahi wehewehe.
(c) Mana arotahi
P = 1/f = 1/-0,5 m = -2 Dioptera
Ko te kaha, te mana rānei o te arotahi he -2 D. Ko te tohu kino he tikanga ko te arotahi e whakamahia ana he arotahi kōpiko, he arotahi wehewehe rānei.
Te Tirohanga Tata me ngā Arotahi Pūpū
Ko te tawhiti tata rawa atu ka kitea mārama e te tangata kite tata ko te 50 cm. Kia taea ai e te tangata te pānui i te tawhiti o te 25 cm pērā i te kanohi noa, whakatauhia (a) te momo karāhe arotahi e whakamahia ana, (b) te roa o te arotahi o te karāhe arotahi, (c) te kaha o te karāhe arotahi.
He tino tata ngā karāhe whakapā ki te kanohi, nō reira kaua e aro ki te tawhiti i waenganui i te karāhe me te kanohi. Ko te tawhiti i waenganui i te mea me te ahua me te karāhe whakapā e kiia ana he rite tonu ki te tawhiti i waenganui i te mea me te ahua me te kanohi.
Kōrero
(a) Momo karaihe i whakamahia
Mō te kaupapa tirohanga tawhiti Kua whakamāramahia ko ngā karāhe arotahi e whakamahia ana hei whakataurite i te tirohanga tata ko ngā karāhe arotahi pūkohu, ngā karāhe arotahi whāiti rānei, ngā karāhe arotahi pai rānei.
(B) Roa arotahi o te arotahi
Kia 25 cm te tawhiti o te mea e tirohia ana ki mua i te kanohi, me hanga e te karu arotahi he ahua i te tawhiti o te 50 cm ki mua i te kanohi. Kei mua i te karu arotahi te ahua, nō reira he poutū, he mariko te ahua (whakatairitehia te whakamārama i roto i te kaupapa whakaahua karaihe kōpiko)
E mōhiotia ana :
Te tawhiti o te mea (s) = 25 cm
Te tawhiti o te ahua (s') = -50 cm (kino nā te mea he mariko)
I pātaihia : Te roa o te arotahi (f) o te karāhe whakapā
Whakautu :
1/h = 1/h + 1/h'
1/f = 1/25 + 1/-50
1/f = 2/50 – 1/50
1/f = 1/50
f = 50/1 = 50 cm = 0,5 mita
Ko te roa arotahi pai ko te arotahi e whakamahia ana he karāhe kōpiko, karāhe hūpeke rānei te arotahi pai rānei.
(c) Mana arotahi
P = 1/f = 1/0,5 = +2 Ngā Diopter
Ko te kaha, te mana rānei o te arotahi he +2 D. Ko te tohu pai ko te arotahi e whakamahia ana he arotahi kōpikopiko, he arotahi hūpeke rānei.