Varifocal lens: strengths and weaknesses

Varifocal lens - ib tug lens nrog ib tug kuj tsis paub meej focal ntev manually. Devices ntawm no hom yuav siv nyob rau hauv cov koob yees duab (nruab nrog xwb lo ntsiab muag ntawm no hom) thiab cov koob yees duab (uas tej zaum yuav yog taag focal ntev los yog ib tug nce mus nce los). Varifocal lens muaj xws li ib tug tib kho qhov muag system uas nws Cheebtsam mechanically tsiv txheeb ze rau txhua tus lwm yam, uas lub ua du hloov (chaw) ntawm focal deb li cas thiab, raws li, nyob rau hauv lub zoom ntau yam ntawm focal lengths. Txawm li cas los, cov sharpness ntawm lub pickup kwv thiab cov aperture tsis sib txawv.

Varifocal lens nrog manually adjustable focal ntev tso cai rau koj yuav hloov ob zaug, uas ua rau nws tau mus kho lub koob yees duab angle rau lub pom duab. Devices nrog tej thaj chaw deb tswj tau hloov lub focal ntev ntawm 6 mus rau 50 lub sij hawm. Tej lo ntsiab muag yog siv rau cov kev soj ntsuam.

Wb to taub, thiab dab tsi yog qhov zoo thiab qhov tsis zoo ntawm xws li ib tug ntaus ntawv raws li ib tug varifocal lens.

Qhov zoo ntawm tus dais no yog qhov tseeb hais tias nws tso cai rau lub kaum sab xis hloov rau ntawm qhov chaw, thaum txhim kho lub koob yees duab. Thiab, ntawm chav kawm, tom qab lub installation ntawm cov koob yees duab tej zaum yuav ua kev kho me ntsis rau focal ntev. Qhov kawg ntawm xws li meej mom. Tam sim no cia peb xav txog qhov tsis zoo.

Lub koob yees duab nrog lens variofokalnym xav tau kev pab nyob rau hauv ib qhov uas tsis yog ib txwm yooj yim vim koj muaj lossi nqa ib ncig ntxiv cov khoom (test saib, roj teeb, lwm yam). Lens hloov yog es nyuab, nws yog tsim nyog los txiav txim seb tus pom piv ntawm cov focal ntev thiab sharpness, thiab cov txheej txheem yog nqa tawm nrog tshwj xeeb cov ntxaij lim dej (kim heev), uas obscure hauv daim duab. Yog li ntawd, cov thawj drawback - nws yog ib tug complex chaw.

Varifocal lens muaj ib tug zuj zus muaj peev xwm (aperture piv) piv rau kev lo ntsiab muag. Qhov no yog tshwj xeeb yog hnov nyob rau hauv ib tug ntau ntawm cov pab kiag li lawm (5-50), cov duab zoo yuav qias neeg rau yav hnub poob. Tsis tshua muaj aperture - nws yog tus thib ob drawback.

Ib tug thib peb drawback varifocal lens yog hais tias nws yog nws thiaj li tau mus defocus los ntawm cov neeg kho tshuab los yog thermal stresses. Raws li ib tug tshwm sim, ib tug ob peb lub hlis yuav tsum ntxiv configuration.

Ib tug thib plaub drawback yog tus nqi ntawm lub lens, nws yog considerably ntau kim tshaj tsau.

Yuav kom saib lub ntsab lug, yog dab tsi varifocal lo ntsiab muag, txawm nws muaj shortcomings, yog heev nrov thiab muaj nyob rau hauv zoo kawg thov tshaj tsau. Txawm li cas los, nws yog tsim nyog sau cia hais tias qhov kev soj ntsuam muab nyob rau hauv no tsab xov xwm tsuas siv rau cov koob yees duab tsim kev soj ntsuam, vim hais tias lawv muaj ib tug xaiv ntawm tsau los yog adjustable lo ntsiab muag. Lub koob yees duab thiab cov tsev video koob yees duab siv heev dua lwm yam adjustable optics.