Igrafu yejika ye-MTF (Modulation Transfer Function) isebenza njengethuluzi lokuhlaziya elibucayi lokuhlola ukusebenza kokubona kwamalensi. Ngokukala ikhono lelensi lokulondoloza ukugqama kumafrikhwensi endawo ahlukahlukene, libonisa ngokubonakalayo izici ezibalulekile zesithombe ezifana nokulungiswa, ukwethembeka kokugqama, kanye nokuvumelana komphetho nomngcele. Ngezansi kunencazelo enemininingwane:
I. Ukuhunyushwa Kwezimbazo Ze-Coordinate nama-Curves
I-eksisi Evundlile (Ibanga ukusuka Maphakathi)
Le eksisi imele ibanga ukusuka maphakathi nesithombe (eliqala ku-0 mm kwesokunxele) ukuya onqenqemeni (iphoyinti lokugcina kwesokudla), likalwa ngamamilimitha (mm). Kumalensi anohlaka olugcwele, ukunakwa okukhethekile kufanele kukhokhwe ebangeni elisuka ku-0 kuye ku-21 mm, elihambisana nengxenye ye-diagonal yenzwa (43 mm). Kumalensi efomethi ye-APS-C, ububanzi obuhambisanayo ngokuvamile bukhawulelwe ku-0 ukuya ku-13 mm, omele ingxenye emaphakathi yesiyingi sesithombe.
I-eksisi eqondile (Inani le-MTF)
I-eksisi eqondile ikhombisa izinga lapho ilensi igcina khona ukugqama, kusukela ku-0 (akukho umehluko ogciniwe) ukuya ku-1 (ukugcinwa kokungafani okuphelele). Inani loku-1 limelela isimo setiyori esikahle esingenakufinyelelwa ekusebenzeni, kuyilapho amanani aseduze noku-1 abonisa ukusebenza okuphakeme.
Izinhlobo Zejika Elibalulekile
I-Spatial Frequency (Iyunithi: amapheya emigqa ngemilimitha, lp/mm):
- Ijika elingu-10 lp/mm (elimelwe umugqa owugqinsi) libonisa ikhono lelensi yokuzalanisa okuhlukile kukonke. Inani le-MTF elingaphezu kuka-0.8 ngokuvamile libhekwa njengelihle kakhulu.
– Ijika elingu-30 lp/mm (elimelwe umugqa omncane) libonisa amandla okuxazulula ilensi nokucijile. Inani le-MTF elingaphezu kuka-0.6 lithathwa njengelihle.
Isikhombisi-ndlela:
- Ulayini Oqinile (I-S / Sagittal noma I-Radial): Imele imigqa yokuhlola enwebeka ngaphandle ukusuka enkabeni (isb., efana nezipika esondweni).
- Ulayini Onamachashazi (M / Meridional noma Tangential): Imelela imigqa yokuhlola ehlelwe yaba yindilinga egxilile (isb, amaphethini afana nendandatho).
II. Imibandela Yokuhlola Ukusebenza
Ukuphakama Kwejika
Isifunda Esimaphakathi (Uhlangothi Lwesokunxele Lwe-eksisi Evundlile): Amanani aphezulu e-MTF awo womabili amajika angu-10 lp/mm kanye nangu-30 lp/mm abonisa ukucatshangelwa okumaphakathi okucijile. Amalensi asezingeni eliphezulu avame ukuzuza amanani amaphakathi e-MTF angaphezu kuka-0.9.
Isifunda Somphetho (Uhlangothi Lwesokudla Lwe-eksisi Evundlile): Ukuncishiswa okuphansi kwamanani e-MTF ngasemiphethweni kubonisa ukusebenza okungcono konqenqema. Isibonelo, inani le-MTF elingunqenqema elingu-30 lp/mm elikhulu kuno-0.4 liyamukeleka, kuyilapho elidlula u-0.6 libhekwa njengelihle kakhulu.
Ijika Ubushelelezi
Ushintsho olushelelayo phakathi kwesikhungo nonqenqema luphakamisa ukusebenza kwesithombe okungaguquki kulo lonke uhlaka. Ukwehla okukhulu kubonisa ukwehla okukhulu kwekhwalithi yesithombe ngasemaphethelweni.
Ukusondelana kwe-S kanye ne-M Curves
Ukuba seduze kwamajika e-sagittal (umugqa oqinile) kanye ne-meridional (umugqa odeshi) kubonisa isilawuli se-astigmatism yelensi. Ukuqondanisa okuseduze kuphumela ku-bokeh yemvelo eyengeziwe kanye nokuphambuka okuncishisiwe. Ukwehlukana okubalulekile kungase kuholele ezinkingeni ezinjengokuphefumula okugxilile noma ama-artifact anemigqa emibili.
III. Izinto Ezengeziwe Ezinomthelela
Usayizi Wembobo
Imbobo Ephezulu (isb., f/1.4): Ingase ikhiqize i-MTF emaphakathi ephezulu kodwa ingaholela ekonakaleni konqenqema ngenxa yokuphambuka kokubona.
Indawo Ekahle (isb, f/8): Ivamise ukunikezela ngokusebenza kwe-MTF okunokulinganisela kakhulu kulo lonke uhlaka futhi kuvame ukugqanyiswa ngokuluhlaza okwesibhakabhaka kumagrafu e-MTF.
Ukuhlukahluka Kwelensi Yokusondeza
Kumalensi okusondeza, amajika e-MTF kufanele ahlolwe ngokwehlukana ku-engeli ebanzi nasekupheleni kwe-telephoto, njengoba ukusebenza kungase kuhluke ngobude bokugxila.
IV. Ukucatshangelwa Okubalulekile
Imikhawulo yokuhlaziywa kwe-MTF
Nakuba i-MTF ihlinzeka ngemininingwane ebalulekile ekuxazululeni nasekuqhathaniseni, ayibaleli okunye ukungapheleli kokubona okufana nokuhlanekezela, ukungalungi kwe-chromatic, noma ukuvuleka. Lezi zici zidinga ukuhlolwa okwengeziwe kusetshenziswa amamethrikhi ahambisanayo.
Ukuqhathaniswa kwe-Cross-Brand
Ngenxa yokuhluka kwezindlela zokuhlola namazinga phakathi kwabakhiqizi, ukuqhathanisa okuqondile kwamajika e-MTF kuzo zonke izinhlobo zemikhiqizo kufanele kugwenywe.
Ijika Ukuzinza kanye ne-Symmetry
Ukushintshashintsha okungavamile noma i-asymmetry kumajika e-MTF kungase kubonise ukungqubuzana kokukhiqiza noma izinkinga zokulawula ikhwalithi.
Isifinyezo Esisheshayo:
Izici zamalensi asebenza kahle kakhulu:
- Lonke ijika le-10 lp/mm lihlala lingaphezulu kuka-0.8
– I-Central 30 lp/mm idlula u-0.6
- I-Edge 30 lp/mm idlula i-0.4
- Amajika e-Sagittal kanye ne-meridional aqondaniswe eduze
- Ukubola okubushelelezi futhi kancane kancane kwe-MTF ukusuka enkabeni kuye konqenqemeni
Ukugxila Kokuhlola Okuyinhloko:
– Inani elimaphakathi 30 lp/mm
- Idigri ye-MTF enqenqemeni yokunciphisa
- Ukusondela kwamajika ka-S no-M
Ukugcina ubuhle kuzo zontathu lezi zindawo kukhombisa ngokunamandla ukwakheka okuphezulu kwe-optical kanye nekhwalithi yokwakha.
Isikhathi sokuthumela: Jul-09-2025