Ayna, insan\u0131n kendisini g\u00f6rmesi i\u00e7in kulland\u0131\u011f\u0131 cam veya maden levhad\u0131r. Mercek ise i\u00e7inden ge\u00e7en paralel \u0131\u015f\u0131nlar\u0131 birbirine yakla\u015ft\u0131ran ya da uzakla\u015ft\u0131ran saydam bir cisimdir. \u0130nsan g\u00f6z\u00fcn\u00fcn g\u00f6rmesini g\u00f6z merce\u011fi sa\u011flar. G\u00f6rme bozuklu\u011funu gidermek i\u00e7in merceklerden olu\u015fan g\u00f6zl\u00fck tak\u0131l\u0131r. Foto\u011fraf makinesi ve b\u00fcy\u00fcte\u00e7 de, mercekle \u00e7al\u0131\u015fan ara\u00e7lard\u0131r. Mikrokskop, teleskop ve di\u011fer bir\u00e7ok \u00f6l\u00e7me ara\u00e7lar\u0131nda mercekler ve aynalar bulunmaktad\u0131r.
\n Bir aynan\u0131n \u00f6n\u00fcnde durup bakarsan\u0131z, y\u00fcz\u00fcn\u00fcz\u00fc g\u00f6rebilirsiniz. Aynan\u0131n durumunu de\u011fi\u015ftirince, ba\u015fka cisimleri de g\u00f6rebilirsiniz. Aynada, \u00f6n\u00fcndeki cismin bir g\u00f6r\u00fcnt\u00fcs\u00fc olu\u015fur.
\n Mercek ve aynalar, g\u00f6r\u00fcnt\u00fc eldesi i\u00e7in kullan\u0131l\u0131rlar. Normal bir d\u00fcz aynada, \u00f6ndeki cismin g\u00f6r\u00fcnt\u00fcs\u00fc, cisimle ayn\u0131 b\u00fcy\u00fckl\u00fckte ve do\u011frultudad\u0131r; fakat sa\u011f\u0131 ve solu yer de\u011fi\u015ftirmi\u015ftir. Sol el, g\u00f6r\u00fcnt\u00fcn\u00fcn sa\u011f taraf\u0131nda g\u00f6r\u00fcn\u00fcr. Aynalar ve merceklerle daha b\u00fcy\u00fck yada daha k\u00fc\u00e7\u00fck g\u00f6r\u00fcnt\u00fcler de elde edilebilir.
\n Mercek, bir ya da iki y\u00fcz\u00fc \u00e7ukur veya t\u00fcmsek olan, cam veya plastikten yap\u0131lm\u0131\u015f bir ara\u00e7t\u0131r. Saydamd\u0131r, yani \u0131\u015f\u0131\u011f\u0131 ge\u00e7irir. Fakat i\u00e7inden ge\u00e7en \u0131\u015f\u0131\u011f\u0131n gidi\u015fini sapt\u0131r\u0131r. Bu sapmaya \u0131\u015f\u0131\u011f\u0131n k\u0131r\u0131lmas\u0131 denir.
\n Ayna ise \u0131\u015f\u0131\u011f\u0131n ge\u00e7emedi\u011fi, parlak bir cisimdir. Y\u00fczleri d\u00fcz veya e\u011fri olabilir. Cam\u0131n bir taraf\u0131n\u0131 g\u00fcm\u00fc\u015f veya ba\u015fka metalle kaplayarak yap\u0131l\u0131r. Ayna, \u00fczerine gelen \u0131\u015f\u0131\u011f\u0131, geldi\u011fi tarafa geri g\u00f6nderir. Bu olaya da \u0131\u015f\u0131\u011f\u0131n yans\u0131mas\u0131 denir.
\n Mercekler ve aynalarla ilgili \u00e7al\u0131\u015fmalara geometrik optik denir. Optik, \u0131\u015f\u0131k bilgisi demektir. Geometri ise, \u015fekiller ve do\u011frultular\u0131 inceleyen bilimdir.farkl\u0131 \u015fekilli mercekler ve aynalar, \u0131\u015f\u0131\u011f\u0131n gidi\u015fini \u00e7e\u015fitli \u015fekillerde de\u011fi\u015ftirirler. Bunlar geometrik optik kurallar\u0131yla belirlenmi\u015ftir.
\n I\u015f\u0131k, bir enerji t\u00fcr\u00fcd\u00fcr. Kitab\u0131n sayfas\u0131ndan g\u00f6ze gelen \u0131\u015f\u0131k, g\u00f6ze enerji ta\u015f\u0131maktad\u0131r. Fakat ayna ve merceklerin \u00e7al\u0131\u015fmas\u0131n\u0131 a\u00e7\u0131klamak i\u00e7in \u0131\u015f\u0131\u011f\u0131n ne oldu\u011funu a\u00e7\u0131klamaya gerek yoktur. I\u015f\u0131\u011f\u0131n ne oldu\u011fu \u00f6\u011frenilmeden \u00e7ok \u00f6nce \u0131\u015f\u0131\u011f\u0131n hareket \u015fekli incelenmi\u015f ve anla\u015f\u0131lm\u0131\u015ft\u0131.
\n I\u015f\u0131k, cam, su ve hava gibi maddelerden ge\u00e7ebilir. Bu maddelere ortam denir. Bo\u015fluk da bir ortamd\u0131r ve \u0131\u015f\u0131k ondan da ge\u00e7ebilir. I\u015f\u0131\u011f\u0131n hareketi, \u0131\u015f\u0131nlardan yola \u00e7\u0131k\u0131larak daha kolay incelenebilir. I\u015f\u0131k \u0131\u015f\u0131n\u0131, \u0131\u015f\u0131\u011f\u0131n \u00e7ok ince bir par\u00e7as\u0131d\u0131r.
\n Bir ortamda yol alan bir \u0131\u015f\u0131n do\u011frusal olarak gider. Fakat ba\u015fka bir ortama ge\u00e7ince, do\u011frultusu de\u011fi\u015fir. Bir ayna veya merce\u011fe \u00e7arp\u0131nca da ayn\u0131 \u015fey olur. Bunlara gelirken ve \u00e7\u0131kt\u0131ktan sonra \u0131\u015f\u0131k do\u011frusal yay\u0131l\u0131r. Fakat i\u00e7inde, k\u0131r\u0131lmalar nedeniyle sapmalar olur.
\n D\u00fcz bir \u00e7izgi \u00e7izin. Bunu bir aynan\u0131n d\u00fcz y\u00fcz\u00fc varsay\u0131n. Sonra bu y\u00fczeye gelen, do\u011frusal bir \u0131\u015f\u0131n \u00e7izin. Bu \u0131\u015f\u0131n, aynaya herhangi bir noktada \u00e7arps\u0131n. Ayn\u0131 noktaya gelen, fakat aynaya dik bir \u0131\u015f\u0131n daha \u00e7izin. Buna dik \u00e7izgi veya normal denir.
\n \u00d6nce \u00e7izilen herhangi \u0131\u015f\u0131n, normalle bir a\u00e7\u0131 yapar ve bu a\u00e7\u0131ya gelme a\u00e7\u0131s\u0131 ad\u0131 verilir. Yans\u0131yan \u0131\u015f\u0131n da, normalle bir a\u00e7\u0131 yapar. Buna yans\u0131ma a\u00e7\u0131s\u0131 denir.
\n Yans\u0131ma yasas\u0131na g\u00f6re, gelme a\u00e7\u0131s\u0131yla yans\u0131ma a\u00e7\u0131s\u0131 birbirine e\u015fittir. B\u00f6ylece, yans\u0131yan \u0131\u015f\u0131n, gelen \u0131\u015f\u0131n\u0131n normalle yapt\u0131\u011f\u0131 a\u00e7\u0131n\u0131n ayn\u0131n\u0131 yapacak \u015fekilde, normalin di\u011fer taraf\u0131na \u00e7izilebilir. Gelme a\u00e7\u0131s\u0131 s\u0131f\u0131r derece ise, gelen \u0131\u015f\u0131nla yans\u0131yan \u0131\u015f\u0131n \u00fcst\u00fcste \u00e7ak\u0131\u015f\u0131r.
\n Gelme a\u00e7\u0131s\u0131 doksan dereceye yak\u0131nsa, yans\u0131yan \u0131\u015f\u0131n da ayna y\u00fcz\u00fcne de\u011ferek gider.
\n Bu olay, bir bilardo topunun masan\u0131n kenar\u0131na \u00e7arp\u0131p, ayn\u0131 a\u00e7\u0131yla di\u011fer tarafa gitmesine benzer.
\n Aynan\u0131n \u00f6n\u00fcne bir cisim koydu\u011fumuzu d\u00fc\u015f\u00fcnelim. Cismin her noktas\u0131ndan ge\u00e7erek gelen \u0131\u015f\u0131nlar aynaya \u00e7arpar.
\n Her \u0131\u015f\u0131n, yans\u0131ma kural\u0131na uyar. Yans\u0131yan \u0131\u015f\u0131nlar, normalin di\u011fer taraf\u0131na do\u011fru yol al\u0131rlar. Aynan\u0131n arkas\u0131ndaki bir noktadan \u0131\u015f\u0131nlar \u00e7\u0131k\u0131yormu\u015f gibi g\u00f6r\u00fcn\u00fcr. Cisim oradaym\u0131\u015f gibi olur. Bu \u015fekilde, aynan\u0131n arkas\u0131nda olu\u015fan g\u00f6r\u00fcnt\u00fcye ger\u00e7ek olmayan g\u00f6r\u00fcnt\u00fc denir.<\/p>\n
KIRILMA<\/p>\n
Aynalardan ba\u015fka, merceklerle de g\u00f6r\u00fcnt\u00fc elde edilebilir. Mercekler cam disklerden kesilir ve sonra y\u00fczeyleri parlat\u0131l\u0131r. I\u015f\u0131k, mercekten ge\u00e7ince, do\u011frultusu de\u011fi\u015fir. Bu olay\u0131 anlamak i\u00e7in, \u0131\u015f\u0131\u011f\u0131n su ve camda nas\u0131l yol ald\u0131\u011f\u0131n\u0131 bilmek gerekir. Bir ortamdan di\u011ferine ge\u00e7erken \u0131\u015f\u0131\u011f\u0131n do\u011frultusu de\u011fi\u015fir. Buna k\u0131r\u0131lma denir.<\/p>\n
Hava ve cam gibi, farkl\u0131 iki ortam\u0131n s\u0131n\u0131r\u0131n\u0131 belirtmek amac\u0131yla d\u00fcz bir \u00e7izgi \u00e7izin.
\n Sonra havadan bir \u0131\u015f\u0131n geldi\u011fini g\u00f6sterin. Cama \u00e7arpt\u0131\u011f\u0131 yerdeki y\u00fczeyin normalini \u00e7izin. I\u015f\u0131k, cam i\u00e7inde yolunu de\u011fi\u015ftirecek ve k\u0131r\u0131lm\u0131\u015f \u0131\u015f\u0131k olacakt\u0131r. K\u0131r\u0131lm\u0131\u015f \u0131\u015f\u0131n\u0131n, normalle yapt\u0131\u011f\u0131 a\u00e7\u0131ya k\u0131r\u0131lma a\u00e7\u0131s\u0131 ad\u0131 verilir. Bu a\u00e7\u0131, normalin di\u011fer taraf\u0131ndad\u0131r.
\n K\u0131r\u0131lma kural\u0131na g\u00f6re k\u0131r\u0131lma a\u00e7\u0131s\u0131, gelme a\u00e7\u0131s\u0131ndan daha k\u00fc\u00e7\u00fckt\u00fcr. Yani, \u0131\u015f\u0131k, normale do\u011fru yakla\u015f\u0131r. E\u011fer a\u00e7\u0131, y\u00fczeye te\u011fet olarak gelirse, yani dik a\u00e7\u0131l\u0131 ise d\u00fcz olarak yoluna devam devam eder.
\n \u015eimdi de camdan gelen herhangi bir \u0131\u015f\u0131n \u00e7izin. Bu \u0131\u015f\u0131n k\u0131r\u0131lacak ve havaya \u00e7\u0131kacakt\u0131r. Havadaki k\u0131r\u0131lma a\u00e7\u0131s\u0131, camdakinden farkl\u0131d\u0131r. K\u0131r\u0131lma kural\u0131na g\u00f6re, k\u0131r\u0131lma a\u00e7\u0131s\u0131, gelme a\u00e7\u0131s\u0131ndan daha b\u00fcy\u00fckt\u00fcr. I\u015f\u0131k, normalden uzakla\u015f\u0131r \u015fekilde yol al\u0131r.
\n Bu iki durum birbirinin benzeridir. Havadaki a\u00e7\u0131, camdaki a\u00e7\u0131dan her zaman daha b\u00fcy\u00fckt\u00fcr. Cam, havadan daha yo\u011fun bir maddedir. Yo\u011fun olan ortamda, a\u00e7\u0131 daha k\u00fc\u00e7\u00fckt\u00fcr. Bu durum di\u011fer ortamlar i\u00e7inde b\u00f6yledir. I\u015f\u0131k, hava ile su aras\u0131nda k\u0131r\u0131l\u0131yorsa, sudaki a\u00e7\u0131 daha k\u00fc\u00e7\u00fckt\u00fcr, \u00e7\u00fcnk\u00fc su, havadan daha yo\u011fundur.
\n I\u015f\u0131k, havadan, daha yo\u011fun bir ortama ge\u00e7erse, o ortam\u0131n yo\u011funlu\u011funa ba\u011fl\u0131 olarak k\u0131r\u0131l\u0131r. Ortam\u0131n yo\u011funlu\u011fu fazlaysa, k\u0131r\u0131lma a\u00e7\u0131s\u0131 k\u00fc\u00e7\u00fck olur; yani \u0131\u015f\u0131k daha fazla b\u00fck\u00fcl\u00fcr. Bu b\u00fck\u00fclme miktar\u0131, k\u0131r\u0131lma indisi denilen bir say\u0131yla g\u00f6sterilir. Yo\u011funlu\u011fu fazla olan ortam\u0131n k\u0131r\u0131lma indisi de b\u00fcy\u00fckt\u00fcr.
\n Aynalarda oldu\u011fu gibi, mercekler de \u0131\u015f\u0131\u011f\u0131n do\u011frultusunu de\u011fi\u015ftirmek i\u00e7in kullan\u0131l\u0131r. Bir cisimden gelen \u0131\u015f\u0131nlar, mercekten ge\u00e7tikten sonra, ba\u015fka bir noktada kesi\u015firler ve sanki oradan \u00e7\u0131k\u0131yor gibi olurlar.<\/p>\n
Yeni noktada bir g\u00f6r\u00fcnt\u00fc olu\u015fur. B\u00fcy\u00fcte\u00e7ler, iki taraf\u0131 da d\u0131\u015fb\u00fckey olan merceklerdir. Bunlar\u0131 kullanarak, G\u00fcne\u015f \u0131\u015f\u0131nlar\u0131n\u0131 bir noktada toplayabilirsiniz. B\u00f6ylece G\u00fcne\u015fin bir g\u00f6r\u00fcnt\u00fcs\u00fcn\u00fc elde edebilirsiniz. Ayn\u0131 \u015fekilde pencerenin g\u00f6r\u00fcnt\u00fcs\u00fc de g\u00f6r\u00fclebilir.
\n Bir b\u00fcy\u00fcte\u00e7le, kolunuzu uzat\u0131p tutarak cisimlere bak\u0131n. Cisimlerden gelen \u0131\u015f\u0131nlar, mercekle g\u00f6z\u00fcn\u00fcz aras\u0131nda bir bir yerde birle\u015fir ve \u0131\u015f\u0131k bu noktadan yeniden g\u00f6z\u00fcn\u00fcze gelir. Cisimlerin ger\u00e7ek g\u00f6r\u00fcnt\u00fclerini g\u00f6r\u00fcrs\u00fcn\u00fcz. Fakat bu g\u00f6r\u00fcnt\u00fcler ba\u015fa\u015fa\u011f\u0131 durumdad\u0131r.
\n K\u00fc\u00e7\u00fck g\u00f6k d\u00fcrb\u00fcnleri, normal d\u00fcrb\u00fcnler ve bir \u00e7ok astronomi d\u00fcrb\u00fcn\u00fcnde, cisimlerin ger\u00e7ek g\u00f6r\u00fcnt\u00fclerini elde etmede d\u0131\u015fb\u00fckey mercekler kullan\u0131l\u0131r. Bunlara ince kenarl\u0131 mercekler ad\u0131 verilir.
\n Cisimler ince kenarl\u0131 merce\u011fe yakla\u015ft\u0131k\u00e7a, g\u00f6r\u00fcnt\u00fcleri, mercekten daha uzakta olu\u015fur. Fakat cisim, merce\u011fe \u00e7ok yak\u0131nsa, ger\u00e7ek bir g\u00f6r\u00fcnt\u00fc olu\u015fmaz. Cisimle ayn\u0131 tarafta, ger\u00e7ek olmayan bir g\u00f6r\u00fcnt\u00fc olu\u015fur. K\u00fc\u00e7\u00fck bir b\u00f6ce\u011fe, b\u00fcyeteci yakla\u015ft\u0131rarak bak\u0131nca, b\u00f6ce\u011fin ger\u00e7ek olmayan bir g\u00f6r\u00fcnt\u00fcs\u00fc g\u00f6r\u00fcl\u00fcr.
\n B\u00fcy\u00fcte\u00e7teki merce\u011fin iki y\u00fcz\u00fc de d\u0131\u015fb\u00fckey de\u011fildir. Biri d\u0131\u015fb\u00fckey di\u011feri d\u00fczd\u00fcr. Bu tip merce\u011fe d\u00fczlem-d\u0131\u015fb\u00fckey mercek denir. Bir y\u00fcz\u00fc d\u0131\u015fb\u00fckey di\u011feri \u00e7ukur da olabilir. Bunlar \u0131\u015f\u0131nlar\u0131n daha az da\u011f\u0131lmas\u0131n\u0131 sa\u011flarlar.
\n Ortas\u0131, kenarlar\u0131ndan daha ince olan mercekler, b\u00fcy\u00fcte\u00e7 olarak kullan\u0131lamaz. Cisimlerin g\u00f6r\u00fcnt\u00fcleri ger\u00e7ek de\u011fildir ve cisimden daha k\u00fc\u00e7\u00fckt\u00fcr. Bunlarla ger\u00e7ek g\u00f6r\u00fcnt\u00fc elde edilemez. G\u00f6zl\u00fcklerdeki mercekler daha \u00e7ok bu t\u00fcrdendir.
\n Bir cismin veya g\u00f6r\u00fcnt\u00fcs\u00fcn\u00fcn foto\u011fraf\u0131n\u0131 \u00e7ekebilirsiniz. Foto\u011fraf makinesinin merce\u011fi iki taraf\u0131 d\u0131\u015fb\u00fckey ince kenarl\u0131 mercektir. Film \u00fczerinde ger\u00e7ek g\u00f6r\u00fcnt\u00fc olu\u015fturur.<\/p>\n
\u0130nsan g\u00f6z\u00fcndeki mercek de ince kenarl\u0131d\u0131r. G\u00f6z\u00fcn a\u011ftabaka denilen arka k\u0131sm\u0131nda, ger\u00e7ek g\u00f6r\u00fcnt\u00fc olu\u015fturur. A\u011ftabakada renkli \u0131\u015f\u0131klar ve g\u00f6r\u00fcnt\u00fcler elektrik sinyallerine d\u00f6n\u00fc\u015f\u00fcr ve beyine gider.
\n Yapay merceklerin \u015fekli de\u011fi\u015femedi\u011fi halde, g\u00f6z merce\u011fi, y\u00fczeylerini de\u011fi\u015ftirebilir. E\u011frili\u011fi \u00e7ok fazlala\u015f\u0131nca, yak\u0131ndaki cisimleri g\u00f6r\u00fcr. E\u011frili\u011fi az olunca, uzaktaki cisimleri g\u00f6r\u00fcr.
\n Fota\u011fraf makinesinin merce\u011finin belirli bir \u015fekli vard\u0131r. Farkl\u0131 uzakl\u0131ktaki cisimlerin g\u00f6r\u00fcnt\u00fcs\u00fcn\u00fc, film \u00fczerine d\u00fc\u015f\u00fcrebilmek i\u00e7in, mercek hareket ettirilir.
\n Merceklerin ve aynalar\u0131n da yap\u0131m kusurlar\u0131 olabilir. Y\u00fczeylerinin e\u011frili\u011fi de\u011fi\u015fkense, bulan\u0131k g\u00f6r\u00fcnt\u00fclerin olu\u015fmas\u0131na yol a\u00e7arlar. Bir noktadan gelen \u0131\u015f\u0131nlar, bir noktada birle\u015fmez, farkl\u0131 yerlerde birle\u015firler. Buna k\u00fcresel sapma ad\u0131 verilir. Bunu \u00f6nlemek i\u00e7in, merceklerin y\u00fczeyi tam k\u00fcresel yap\u0131lmaz.
\n Renk sapmas\u0131 nedeniyle de bulan\u0131k g\u00f6r\u00fcnt\u00fc olu\u015fabilir. \u00c7\u00fcnk\u00fc merce\u011fin yap\u0131ld\u0131\u011f\u0131 cam, farkl\u0131 renkli \u0131\u015f\u0131klar\u0131, farkl\u0131 miktarlarda k\u0131rar. Bu y\u00fczden cisimlerin g\u00f6r\u00fcnt\u00fcs\u00fc bulan\u0131k olur. G\u00f6r\u00fcnt\u00fc, renkli \u015feritler bi\u00e7iminde g\u00f6r\u00fcl\u00fcr. Bu sapma, birka\u00e7 merce\u011fi bir arada kullanarak d\u00fczeltilebilir. Kullan\u0131lan camlar\u0131n k\u0131r\u0131lma indisleri farkl\u0131 se\u00e7ilir.
\n Merce\u011fe gelen \u0131\u015f\u0131nlar\u0131n hepsi di\u011fer tarafa ge\u00e7mez. Bir k\u0131sm\u0131 da geri yans\u0131r. Bu durum pencere cam\u0131nda g\u00f6r\u00fclebilir. Bunlar, optik ara\u00e7larda istenmeyen yanl\u0131\u015f g\u00f6r\u00fcnt\u00fclere yol a\u00e7abilir. Bu yans\u0131may\u0131 azaltmak i\u00e7in mercekler, \u0131\u015f\u0131\u011f\u0131 ge\u00e7iren, fakat yans\u0131tmayan \u00f6zel bir kimyasal maddeyle kaplan\u0131r.
\n I\u015f\u0131k, yo\u011fun bir ortamdan, az yo\u011fun ortama ge\u00e7erse, y\u00fczeyin normalinden uzakla\u015farak k\u0131r\u0131l\u0131r. Bu k\u0131r\u0131lma o kadar fazla olabilir ki , k\u0131r\u0131lan \u0131\u015f\u0131n, y\u00fczeye te\u011fet olur. Bu durum kritik a\u00e7\u0131 denilen belli bir geli\u015f a\u00e7\u0131s\u0131nda olur. Geli\u015f a\u00e7\u0131s\u0131, kritik a\u00e7\u0131dan daha b\u00fcy\u00fckse, k\u0131r\u0131lma olmaz. Gelen b\u00fct\u00fcn \u0131\u015f\u0131k, yeniden \u00e7ok yo\u011fun ortama yans\u0131r. Buna tam yans\u0131ma ad\u0131 verilir.
\n Mercek: Optik g\u00f6r\u00fcnt\u00fcler olu\u015fturmak i\u00e7in kullan\u0131lan, genellikle k\u00fcresel y\u00fczeylerle s\u0131n\u0131rl\u0131, camdan ya da \u0131\u015f\u0131k k\u0131r\u0131c\u0131 bir maddeden yap\u0131lm\u0131\u015f hacim.
\n Dalga ve titr: Ses\u00f6tesi mercek, ses\u00f6tesi titre\u015fimlerin h\u0131z\u0131n\u0131n, ses\u00f6tesi inceleme ortam\u0131ndakinden (su, insan v\u00fccudu) \u00e7ok farkl\u0131 oldu\u011fu bir gere\u00e7 i\u00e7inde (pleksiglas, kau\u00e7uk) ger\u00e7ekle\u015ftirilen ve bu nedenle, ses\u00f6tesi titre\u015fimler i\u00e7in optik merceklerin \u0131\u015f\u0131\u011fa g\u00f6sterdi\u011fine benzer \u00f6zellikler g\u00f6steren d\u00fczenek. (Ses\u00f6tesi mercekler, akustik mikroskopta kullan\u0131l\u0131r.)
\n Elektron: Elektron merce\u011fi, kondansat\u00f6rlerden (elektrostatik mercek), bobin ya da elekrom\u0131knat\u0131slardan (elektromanyetik mercek) olu\u015fan ve optik merceklerin \u0131\u015f\u0131k demetlerini sapt\u0131rd\u0131\u011f\u0131 gibi, y\u00fckl\u00fc par\u00e7ac\u0131k demetlerini de sapt\u0131ran eksenel bak\u0131\u015f\u0131ml\u0131 d\u00fczenek. (Elektron ak\u0131mlar\u0131n\u0131 yak\u0131nsatmaya olanak veren elektron mercekleri bir\u00e7ok ayg\u0131tta, \u00f6zellikle elektron mikroskoplar\u0131nda kullan\u0131l\u0131r.)
\n Mad: Kenarlara do\u011fru incelen, nispeten az kal\u0131nl\u0131kta mineral y\u0131\u011f\u0131n\u0131.
\n Oftalmol: Yapay g\u00f6zmerce\u011fi genellikle katarakt nedeniyle \u00e7\u0131kar\u0131lan g\u00f6zmerce\u011finin yerine tak\u0131lan implant.(Afaki durumunda g\u00f6zl\u00fckle yap\u0131lan d\u00fczeltmeye g\u00f6re \u00e7ok daha iyi oldu\u011fundan b\u00fcy\u00fck bir geli\u015fme g\u00f6stermi\u015ftir:g\u00f6rme alan\u0131n\u0131 tam g\u00f6r\u00fcr ve g\u00f6r\u00fcnt\u00fclerin boyutlar\u0131n\u0131 da b\u00fcy\u00fctmez.)
\n Opt: Basamakl\u0131 mercek ya da Fresnel merce\u011fi merkezi bir mercek ile k\u0131r\u0131c\u0131 ya da yans\u0131t\u0131c\u0131 \u00e7e\u015fitli halkalardan olu\u015fan ve ko\u015fut \u0131\u015f\u0131kl\u0131 geni\u015f bir demet elde etmek i\u00e7in deniz fenerlerinde kullan\u0131lan optik sistem.
\n Radyotekn: Radyoelektriksel mercek, bir radyoelektrik dalgas\u0131n\u0131n yay\u0131lmas\u0131nda, faz gecikmeleri olu\u015fturmaya yarayan ve b\u00f6ylece yak\u0131nsama ya da \u0131raksama etkileri yaratan d\u00fczenek; faz gecikmelerinin de\u011feri gelme a\u00e7\u0131s\u0131na ya da d\u00fczenekten ge\u00e7en \u0131\u015f\u0131n\u0131n konumuna ba\u011fl\u0131d\u0131r.
\n Ansikl. Opt: Bir mercek, genellikle k\u00fcresel olan iki y\u00fczeyle (diyoptrlar) s\u0131n\u0131rl\u0131, k\u0131r\u0131c\u0131 ve saydam bir ortamdan olu\u015fur. Do\u011furucular\u0131 ko\u015fut olan iki silindir y\u00fczeyle s\u0131n\u0131rl\u0131 mercekler de vard\u0131r.
\n Mercek: Bir cisimden gelen \u0131\u015f\u0131k \u0131\u015f\u0131nlar\u0131n\u0131 odaklayarak cismin optik g\u00f6r\u00fcnt\u00fcs\u00fcn\u00fc olu\u015fturmaya yarayan cam ya da bir ba\u015fka saydam malzemeye denir. Foto\u011fraf makinesi, g\u00f6zl\u00fck, mikroskop, teleskop gibi ayg\u0131tlarda merceklerden yararlan\u0131l\u0131r. I\u015f\u0131k, merce\u011fin i\u00e7inde hava da oldu\u011fundan daha yava\u015f ilerler;
\n bu nedenle de \u0131\u015f\u0131k demeti hem merce\u011fe girerken hem de mercekten \u00e7\u0131karken k\u0131r\u0131l\u0131r, yani aniden do\u011frultu de\u011fi\u015ftirir; merceklerin \u0131\u015f\u0131k \u0131\u015f\u0131nlar\u0131n\u0131 odaklama etkisi de bu olgudan kaynaklan\u0131r.
\n Merceklerde, duyarl\u0131 bi\u00e7imde i\u015flenmi\u015f iki kar\u015f\u0131t y\u00fczey vard\u0131r; bu y\u00fczlerin her ikisi de k\u00fcresel olabilece\u011fi gibi, biri k\u00fcresel \u00f6teki d\u00fczlemsel olabilir. Mercekler, y\u00fczeylerinin bi\u00e7imine g\u00f6re, \u00e7ift d\u0131\u015fb\u00fckey, d\u00fczlem d\u0131\u015fb\u00fckey, yak\u0131nsak aymercek, \u00e7ift i\u00e7b\u00fckey, d\u00fczlem i\u00e7b\u00fckey ve \u0131raksak aymercek olarak s\u0131n\u0131fland\u0131r\u0131l\u0131r. Merce\u011fin e\u011fri y\u00fczeyi, gelen \u0131\u015f\u0131k demetindeki farkl\u0131 \u0131\u015f\u0131nlar\u0131n farkl\u0131 a\u00e7\u0131larla k\u0131r\u0131lmas\u0131na neden olur ve bu da, \u0131\u015f\u0131k demetindeki paralel \u0131\u015f\u0131nlar\u0131n tek bir noktaya do\u011fru y\u00f6nelmesine (yak\u0131nsama) ya da bu noktadan \u00f6teye do\u011fru y\u00f6nelmesine (\u0131raksama) yol a\u00e7ar. Bu noktaya merce\u011fin odak noktas\u0131 ya da asal oda\u011f\u0131 denir. Bir cisimden yay\u0131lan ya da yans\u0131yarak gelen \u0131\u015f\u0131k \u0131\u015f\u0131nlar\u0131n\u0131n k\u0131r\u0131lmas\u0131, bu \u0131\u015f\u0131nlar\u0131n farkl\u0131 bir yerden geliyormu\u015f gibi alg\u0131lanmas\u0131na yol a\u00e7ar ve nitekim bu farkl\u0131 yerde de cismin optik bir g\u00f6r\u00fcnt\u00fcs\u00fc olu\u015fur. Bu g\u00f6r\u00fcnt\u00fc ger\u00e7ek (foto\u011fraf\u0131 \u00e7ekilebilir ya da ekran yans\u0131t\u0131labilir) olabilece\u011fi gibi sanal da (mikroskopta oldu\u011fu gibi, ancak merce\u011fin i\u00e7inden bak\u0131larak g\u00f6r\u00fclebilir) olabilir. Cismin optik g\u00f6r\u00fcnt\u00fcs\u00fc cismin kendisinden daha b\u00fcy\u00fck ya da daha k\u00fc\u00e7\u00fck olabilir; bu durum, merce\u011fin odak uzakl\u0131\u011f\u0131na ve cisim ile mercek aras\u0131ndaki uzakl\u0131\u011fa ba\u011fl\u0131d\u0131r.
\n Duyarl\u0131 ve net bir g\u00f6r\u00fcnt\u00fc olu\u015fturabilmek i\u00e7in genellikle tek bir mercek yetmez; bu nedenle de \u00f6rne\u011fin teleskoplarda, mikroskoplarda ya da foto\u011fraf makinelerinde, de\u011fi\u015fik mercek kombinasyonlar\u0131ndan yararlan\u0131l\u0131r. Bu t\u00fcr mercek gruplar\u0131ndaki merceklerden baz\u0131lar\u0131 d\u0131\u015fb\u00fckey ve baz\u0131lar\u0131 i\u00e7b\u00fckey olabilece\u011fi gibi bunlar\u0131n baz\u0131lar\u0131 k\u0131rma ya da ay\u0131rma g\u00fcc\u00fc y\u00fcksek ve baz\u0131lar\u0131 da k\u0131rma ya da ay\u0131rma g\u00fcc\u00fc d\u00fc\u015f\u00fck camdan yap\u0131lm\u0131\u015f olabilir. Gruptaki mercekler, her birinin sap\u0131nc\u0131 (aberasyon) istenen d\u00fczeyde olacak ve net bir g\u00f6r\u00fcnt\u00fc elde edilebilecek bi\u00e7imde, duyarl\u0131l\u0131kla saptanm\u0131\u015f uzakl\u0131klarda yerle\u015ftirilir ya da \u00fcst \u00fcste yap\u0131\u015ft\u0131r\u0131l\u0131r. Mercekler yerle\u015ftirilirken y\u00fczeylerinin e\u011fiklik merkezinin asal eksen ya da optik eksen denen d\u00fcz bir hatt\u0131n \u00fczerinde bulunmas\u0131na \u00f6zen g\u00f6sterilir.
\n Mercekler \u00e7ok de\u011fi\u015fik \u00e7aplarda yap\u0131labilir; \u00f6rne\u011fin mikroskoplarda 0,16 cm, teleskoplarda ise 100 cm\u2019lik mercekler kullan\u0131labilir. Daha b\u00fcy\u00fck teleskoplarda mercek yerine i\u00e7b\u00fckey aynalardan yararlan\u0131l\u0131r.<\/p>\n
Mercek \u00c7e\u015fitleri:<\/p>\n
Y\u00fczlerinin durumuna ve bi\u00e7imine g\u00f6re, \u00fc\u00e7\u00fc ince kenarl\u0131, \u00fc\u00e7\u00fc de kal\u0131n kenarl\u0131 olmak \u00fczere alt\u0131 t\u00fcr mercek ay\u0131rt edilir. Y\u00fczlerin C1 ve C2 e\u011frilik merkezlerinden ge\u00e7en do\u011fruya merce\u011fin ana ekseni ad\u0131 verilir ( y\u00fczlerden biri d\u00fczlemse, merkezlerden biri sonsuza gider). S1 S2 uzunlu\u011fu merce\u011fin kal\u0131nl\u0131\u011f\u0131d\u0131r. Kal\u0131nl\u0131k, y\u00fczlerin e\u011frilik yar\u0131 \u00e7ap\u0131 kar\u015f\u0131s\u0131nda \u00f6nemsiz kal\u0131yorsa, mercek ince, kar\u015f\u0131t bir durum s\u00f6z konusu oldu\u011funda da kal\u0131nd\u0131r. \u0130nce kenarlar\u0131n baz\u0131 \u00f6zellikleri, incelenmesi daha g\u00fc\u00e7 olan kal\u0131n merceklere de yayg\u0131nla\u015ft\u0131r\u0131labilir.
\n \u0130nce mercekler: \u0130nce mercekler durumunda S1 ve S2 noktalar\u0131n\u0131n, ana eksen \u00fczerinde bulunan ve merce\u011fin optik merkezi ad\u0131 verilen bir O noktas\u0131nda birbiriyle kar\u015f\u0131la\u015ft\u0131klar\u0131 kabul edilir. \u0130nce mercekler ince kenarl\u0131 ya da kal\u0131n kenarl\u0131 olabilirler. \u0130nce kenarl\u0131lar yak\u0131nsak merceklerdir: Ana eksene paralel olan her \u0131\u015f\u0131n demeti bir F noktas\u0131nda yak\u0131nsayarak g\u00f6r\u00fcn\u00fcr hale ge\u00e7er. Kal\u0131n kenarl\u0131lar s\u00f6z konusu oldu\u011fundaysa mercek \u0131raksakt\u0131r. Bu sonu\u00e7lar k\u0131r\u0131lma yasalar\u0131ndan kaynaklan\u0131r. Bir merce\u011fin, bir cismin tam belirgin (net) bir g\u00f6r\u00fcnt\u00fcs\u00fcn\u00fc vermesi i\u00e7in, cismin her noktas\u0131na g\u00f6r\u00fcnt\u00fcn\u00fcn bir noktas\u0131 denk d\u00fc\u015fmelidir: Bu durumda sisteme stigmatik ad\u0131 verilir. Bunu ger\u00e7ekle\u015ftirmek \u00e7ok g\u00fc\u00e7, hatta b\u00fcy\u00fck boyutlu cisimler s\u00f6z konusu oldu\u011funda olanaks\u0131zd\u0131r. Bununla birlikte, g\u00f6r\u00fcnt\u00fcy\u00fc olu\u015fturmak \u00fczere kullan\u0131lan \u0131\u015f\u0131nlar\u0131n ana eksen ile yapt\u0131klar\u0131 e\u011fim az oldu\u011fu ve mercekten optik merkeze yak\u0131n ge\u00e7tikleri zaman (Gauss ko\u015fullar\u0131) yeterli derecede iyi bir sonu\u00e7 elde edilir.
\n Bu durumda, ana eksene dik bir d\u00fcz cisimden, eksene dik bir d\u00fcz g\u00f6r\u00fcnt\u00fc sa\u011flan\u0131r. G\u00f6r\u00fcnt\u00fc, bu noktaya yerle\u015ftirilmi\u015f olan bir ekran \u00fczerinde g\u00f6zlenebiliyorsa buna ger\u00e7ek g\u00f6r\u00fcnt\u00fc, kar\u015f\u0131t durumdaysa zahir g\u00f6r\u00fcnt\u00fc ad\u0131 verilir.
\n Yak\u0131nsak mercekler: Ana eksene paralel \u0131\u015f\u0131nlar\u0131n yak\u0131nsama noktas\u0131 olan F noktas\u0131na ana g\u00f6r\u00fcnt\u00fc-odak ad\u0131 verilir. Bu odak ana eksen do\u011frultusunda, sonsuzdaki bir nesne-noktan\u0131n g\u00f6r\u00fcnt\u00fcs\u00fcd\u00fcr.(uygulamada nesne-noktan\u0131n g\u00f6r\u00fcnt\u00fcs\u00fcn\u00fcn tam F \u00fczerinde olmas\u0131 i\u00e7in, bu noktan\u0131n OF uzunlu\u011funun on kat\u0131 kadar bir uzakl\u0131kta bulunmas\u0131 \u00e7o\u011funlukla yeterli olur.)
\n \u00d6te yandan, ana eksen \u00fczerinde \u00f6yle bir F noktas\u0131 da belirlenebilir ki, F\u2019ten \u00e7\u0131kan \u0131\u015f\u0131nlar mercekten ge\u00e7tikten sonra ana eksene paralel bir \u0131\u015f\u0131n demeti olu\u015ftururlar. S\u00f6z konusu F noktas\u0131n\u0131n g\u00f6r\u00fcnt\u00fcs\u00fc bu durumda ana eksen \u00fczerinde sonsuzda bulunur ve F noktas\u0131na ana nesne-odak ad\u0131 verilir.
\n OF ve OF\u2019 uzunluklar\u0131 s\u0131ras\u0131yla merce\u011fin nesne-odak uzakl\u0131\u011f\u0131 ve g\u00f6r\u00fcnt\u00fc-odak uzakl\u0131\u011f\u0131 olarak adland\u0131r\u0131l\u0131r. Ana eksene e\u011fik olarak gelen paralel bir \u0131\u015f\u0131n demeti, ana eksene F\u2019 nokatas\u0131nda dik olan bir d\u00fczlemde ki bir H\u2019 noktas\u0131nda (ikincil g\u00f6r\u00fcnt\u00fc-odak) yak\u0131nsar; bu d\u00fczlem, g\u00f6r\u00fcnt\u00fc-odak d\u00fczlemidir. Ayn\u0131 bi\u00e7imde, ikincil nesne-odak ve nesne-odak d\u00fczlemi tan\u0131mlanabilir.
\n B\u0130R NESNEN\u0130N YAKINSAK B\u0130R MERCEK ARACILI\u011eIYLA VER\u0130LM\u0130\u015e G\u00d6R\u00dcNT\u00dcS\u00dcN\u00dcN GEOMETR\u0130K OLARAK ELDE ED\u0130LMES\u0130. Basit olarak bir AB do\u011fru par\u00e7as\u0131yla g\u00f6sterilmi\u015f olan d\u00fcz bir nesne ve mercek konumu ve boyutlar\u0131 \u00e7izim yoluyla saptanabilen bir A\u2019 B\u2019 g\u00f6r\u00fcnt\u00fcs\u00fc verir(\u00c7izim kolayl\u0131\u011f\u0131 i\u00e7in baz\u0131 noktalar ana eksenden uzakla\u015fm\u0131\u015f olsalar bile, Gauss ko\u015fullar\u0131n\u0131n ger\u00e7ekli\u011fi kabul edilir). Merce\u011fin ana ekseni \u00fcst\u00fcnde bir A noktas\u0131yla, bu eksene dik olan AB do\u011frusu se\u00e7ilir. Aranan g\u00f6r\u00fcnt\u00fc, merce\u011fin ana eksenine dik olan ve B noktas\u0131ndan B\u2019 g\u00f6r\u00fcnt\u00fcs\u00fc bilindi\u011finden tam olarak saptanan bir A\u2019B\u2019 do\u011fru par\u00e7as\u0131d\u0131r. B\u2019 elde etmek i\u00e7in, B\u2019den \u00e7\u0131kan demetin iki \u00f6zel \u0131\u015f\u0131n\u0131 g\u00f6z \u00f6n\u00fcne al\u0131n\u0131r(geometride, bir nokta, bilinen iki do\u011frunun kesi\u015fmesiyle tam olarak belirlenir);s\u00f6zgelimi, F noktas\u0131ndan ge\u00e7erek gelen \u0131\u015f\u0131nla, O optik merkezden ge\u00e7erek gelen \u0131\u015f\u0131n kullan\u0131labilir. Bu iki \u0131\u015f\u0131n\u0131n kesi\u015fme noktas\u0131, aranan B\u2019 noktas\u0131d\u0131r(B\u2019den ge\u00e7en \u0131\u015f\u0131nlar\u0131n t\u00fcm\u00fc, mercekten ge\u00e7tikten sonra B\u2019 noktas\u0131ndanda ge\u00e7erler). Nesnenin konumuna g\u00f6re g\u00f6r\u00fcnt\u00fc ger\u00e7ek yada zahiridir.
\n Iraksak mercekler:Ana eksene paralel \u0131\u015f\u0131nl\u0131 bir demete F\u2019 noktas\u0131ndan \u00e7\u0131k\u0131yormu\u015f gibi olan \u0131raksak bir demet denk d\u00fc\u015fer; bu noktaya anag\u00f6r\u00fcnt\u00fc-odak denir. Ana nesne-odak ad\u0131 verilen birF noktas\u0131nda, zahiri olarak yak\u0131nsayacak bi\u00e7imde bir demetin mercek \u00fcst\u00fcne g\u00f6nderilmesiyle, ana eksene paralel olarak ortaya \u00e7\u0131kan bir demet elde edilir. Yak\u0131nsak mercekteki gibi, \u0131raksak merceklerde de g\u00f6r\u00fcnt\u00fc-odak ve nesne-odak d\u00fczlemleri ile g\u00f6r\u00fcnt\u00fc-odak ve nesne-odak uzakl\u0131klar\u0131\u2019n\u0131n tan\u0131m\u0131 yap\u0131l\u0131r.
\n B\u0130R NESNEN\u0130N IRAKSAK B\u0130R MERCEK ARACILI\u011eIYLA VER\u0130LM\u0130\u015e G\u00d6R\u00dcNT\u00dcS\u00dcN\u00dcN GEOMETR\u0130K OLARAK ELDE ED\u0130LMES\u0130. Burada da yak\u0131nsak mercekler i\u00e7in yap\u0131lan i\u015flemin ayn\u0131s\u0131 ger\u00e7ekle\u015ftirilir:B noktas\u0131ndan \u00e7\u0131kan iki \u00f6zel \u0131\u015f\u0131n (s\u00f6zgelimi,biri O\u2019 dan, \u00f6teki F\u2019 den ge\u00e7en ) kullan\u0131l\u0131r. Birincisi sapmaz;ikincisiyse ana eksene paralel olarak \u00e7\u0131kan bir \u0131\u015f\u0131n gibi sapar. Bu iki \u0131\u015f\u0131n\u0131n kesi\u015fme noktas\u0131, aranan B\u2019 noktas\u0131d\u0131r. Nesnenin konumuna g\u00f6re, g\u00f6r\u00fcnt\u00fc ger\u00e7ek yada zahiridir.<\/p>\n
Mercek Sap\u0131n\u00e7lar\u0131: <\/p>\n
Mercek Gauss ko\u015fullar\u0131na uygun olarak kullan\u0131lmad\u0131\u011f\u0131 zaman, elde edilen g\u00f6r\u00fcnt\u00fcler bozulur ve sap\u0131n\u00e7 (aberasyon) diye adland\u0131r\u0131lan olaylar g\u00f6r\u00fcl\u00fcr.
\n Renkser Sap\u0131n\u00e7: Beyaz \u0131\u015f\u0131kta ayd\u0131nlanm\u0131\u015f bir nesne, az ya da \u00e7ok \u00f6nemli renklenme g\u00f6steren bir g\u00f6r\u00fcnt\u00fc verir. Buna merce\u011fin k\u0131r\u0131lma indisinin, \u0131\u015f\u0131\u011f\u0131n dalga boyuyla birlikte de\u011fi\u015fmesi yol a\u00e7ar. Beyaz \u0131\u015f\u0131k farkl\u0131 renklerdeki belirli say\u0131da \u0131\u015f\u0131n\u0131m\u0131n \u00fcst \u00fcste gelmesi bi\u00e7iminde ele al\u0131n\u0131rsa (tek bile\u015fenli [tek renkli] \u0131\u015f\u0131n\u0131m) bu \u0131\u015f\u0131\u011f\u0131n k\u0131rm\u0131z\u0131 \u0131\u015f\u0131n\u0131mlar\u0131 morunkilerle ayn\u0131 noktaya yak\u0131nsamazlar. B\u00f6ylelikle farkl\u0131 renklerde bir\u00e7ok g\u00f6r\u00fcnt\u00fc elde edilir. Bunlar ancak k\u0131smen \u00fcst \u00fcste gelirler.
\n Geometrik Sap\u0131n\u00e7: B\u00fcy\u00fck a\u00e7\u0131l\u0131ml\u0131 bir demet kullan\u0131ld\u0131\u011f\u0131nda bir nesne noktas\u0131, bir P\u2019g\u00f6r\u00fcnt\u00fc noktas\u0131 verir; \u00e7\u00fcnk\u00fc merce\u011fin kenar b\u00f6lgelerinden ge\u00e7en \u0131\u015f\u0131nlar eksene yak\u0131n b\u00f6lgeden ge\u00e7enlere oranla daha \u00e7ok parlar; yak\u0131nsak bir merce\u011fin merkez b\u00f6lgesine g\u00f6re kenarlar\u0131 da yak\u0131nsak, \u0131raksak bir merce\u011fin kenarlar\u0131 da daha \u0131raksakt\u0131r (k\u00fcresel sap\u0131nma). Yukar\u0131daki bozulma d\u00fczeltilse bile, mercek, ana eksenin yak\u0131n\u0131nda bulunan bir noktan\u0131n g\u00f6r\u00fcnt\u00fcs\u00fcn\u00fc, bu noktadan \u00e7\u0131kan demet \u00e7ok geni\u015fse normal bi\u00e7iminde vermez. Bi\u00e7imi kuyruklu y\u0131ld\u0131z\u0131 (komet) an\u0131msatan bir leke elde edilir; bu sap\u0131nca koma ad\u0131 verilir.
\n Dar demetlerin kullan\u0131lmas\u0131, kusurlardan ar\u0131nm\u0131\u015f g\u00f6r\u00fcnt\u00fclerin elde edilmesi i\u00e7in yeterli olmaz. Ger\u00e7ek merce\u011fin ana eksenine \u00e7ok e\u011fimli olarak gelen ince bir \u0131\u015f\u0131k demetiyle nesne-noktan\u0131n iki ayr\u0131 g\u00f6r\u00fcnt\u00fcs\u00fc meydana gelir. Astigmatizm ad\u0131 verilen bu sap\u0131n\u00e7 bir dairesel yar\u0131 \u00e7aplar\u0131n\u0131 ayn\u0131 anda net bir g\u00f6r\u00fcnt\u00fcs\u00fc elde edilmesinin olanaks\u0131zla\u015fmas\u0131ndan kaynaklan\u0131r: Yatay \u00e7ap belirgin olunca dikey \u00e7ap belirsizdir; bu durumun tersi de s\u00f6z konusudur.
\n Ayr\u0131ca bu kusurlar d\u00fczeltilse bile ana eksene dik olan geni\u015f bir d\u00fczlemsel y\u00fczeyin g\u00f6r\u00fcnt\u00fcs\u00fc e\u011fri bir y\u00fczeydir. Bu kusara alan e\u011frili\u011fi ad\u0131 verilir.
\n Yukar\u0131da s\u00f6z\u00fc edilen kusurlar giderildikten sonra ba\u015fkalar\u0131 ortaya \u00e7\u0131kabilir; bunlar\u0131n sonucu olarak g\u00f6r\u00fcnt\u00fclerin do\u011frusal b\u00fcy\u00fcmesi, merce\u011fin ekseninden uzakla\u015ft\u0131k\u00e7a artar. B\u00f6ylece, eksenden ge\u00e7meyen bir do\u011fru \u00e7izgi i\u00e7b\u00fckeyli\u011fi g\u00f6r\u00fcnt\u00fcn\u00fcn merkezine do\u011fru (f\u0131\u00e7\u0131 bi\u00e7iminde b\u00fck\u00fclme) ya da ters y\u00f6nde (hilal bi\u00e7iminde b\u00fck\u00fclme) d\u00f6nm\u00fc\u015f olan e\u011fri bir \u00e7izgi verir.
\n Bu sap\u0131n\u00e7lar\u0131n azalt\u0131lmas\u0131 sorunu \u00e7ok g\u00fc\u00e7t\u00fcr, \u00e7\u00fcnk\u00fc d\u00fczeltilmeleri i\u00e7in gerekli ko\u015fullar \u00e7o\u011fu kez birbirine kar\u015f\u0131tt\u0131r. G\u00f6zl\u00fck\u00e7\u00fcler, iste\u011fe g\u00f6re, \u00e7e\u015fitli merceklerin bi\u00e7imlerinden, maddelerinden ve kar\u015f\u0131l\u0131kl\u0131 yerlerinden yararlanmak amac\u0131yla bir \u00e7ok merce\u011fi bir arada kullan\u0131rlar.<\/p>\n
\u00d6zel Mercekler:<\/p>\n
Silindirik mercekler, silindir bir y\u00fczey ve bir d\u00fczlemle, k\u00fcresel-silindirik mercekler bir k\u00fcre ve silindirle s\u0131n\u0131rland\u0131r\u0131lm\u0131\u015ft\u0131r. Baz\u0131 merceklerse y\u00fczlerinden biri bir d\u00fczlem ya da bir k\u00fcreyle de\u011fi\u015ftirilebilen, iki tor y\u00fczeyiyle s\u0131n\u0131rland\u0131r\u0131lm\u0131\u015ft\u0131r; bu tor mercekler \u00f6zellikle g\u00f6zlerdeki astigmat durumunun d\u00fczeltilmesine yararlar. Fresnel\u2019in deniz fenerlerinde kullan\u0131lan kademeli mercekleri eksenin k\u00fcresel sap\u0131nc\u0131n\u0131n k\u0131smen, ama yeterli olarak giderilmesini sa\u011flar. Merkez b\u00f6lgesinin kal\u0131nl\u0131\u011f\u0131n\u0131n azalt\u0131lmas\u0131, b\u00fcy\u00fck \u00e7apta uygulamalar\u0131n ger\u00e7ekle\u015ftirilmesine olanak verir. B\u00f6ylelikle \u0131s\u0131nma ve b\u00fcy\u00fck enerji yitimi tehlikesi de azalt\u0131lm\u0131\u015f olur. <\/p>\n
Merceklerin Kullan\u0131ld\u0131\u011f\u0131 Yerler:<\/p>\n
D\u0131\u015fb\u00fckey mercekler foto\u011fraf makinelerinde kullan\u0131l\u0131r. Foto\u011fraf makinesinde, merce\u011fin hemen arkas\u0131nda bir foto\u011fraf filmi bulunur. Foto\u011fraf makinesinin boyutlar\u0131 ve film ile mercek aras\u0131ndaki uzakl\u0131k g\u00f6z \u00f6n\u00fcnde tutlacak olursa, foto\u011fraf\u0131 \u00e7ekilecek g\u00f6r\u00fcnt\u00fcn\u00fcn makineye olduk\u00e7a uzak oldu\u011fu kavranabilir. \u0130\u015fte mercek bu uzaktaki cisimlerden, insanlardan ya da manzartadan gelen \u0131\u015f\u0131k \u0131\u015f\u0131nlar\u0131n\u0131 toplayarak ard\u0131ndaki film \u00fczerinde \u00f6daklar ve burada g\u00f6r\u00fcnt\u00fcn\u00fcn ba\u015f a\u015fa\u011f\u0131, yani ters bir resmini olu\u015fturur. Refleks tipi makinelerde, birincisinin ayn\u0131s\u0131 ikinci bir mercek daha bulunur; bu mercek, ayn\u0131 g\u00f6r\u00fcnt\u00fcy\u00fc arkadaki bir cam ekran\u0131n \u00fczerine d\u00fc\u015f\u00fcrerek foto\u011fraf\u00e7\u0131n\u0131n odaklama ayar\u0131n\u0131 iyi yapabilmesine ve \u00e7ekece\u011fi resmi tam olarak g\u00f6rebilmesini sa\u011flar.
\n Zoom objektifli\u011fi makinelerde ise odak uzakl\u0131\u011f\u0131n\u0131n de\u011fi\u015fmesini sa\u011flayan ayr\u0131 bir mercek sistemi bulunur.
\n Sinema filmi g\u00f6stericilerinden ya da slayt makinelerinde parlak bi\u00e7imde ayd\u0131nlat\u0131lm\u0131\u015f filmden gelen \u0131\u015f\u0131k \u00fczerine d\u00fc\u015f\u00fcrmeye yarayan d\u0131\u015fb\u00fckey mercekler kullan\u0131l\u0131r. Film yaln\u0131zca 35 mm geni\u015fli\u011findedir, ama ekran \u00fczerine d\u00fc\u015f\u00fcr\u00fclen g\u00f6r\u00fcnt\u00fcn\u00fcn geni\u015fli\u011fi metrelerce olabilir.<\/p>\n
G\u00f6zdeki Mercek :<\/p>\n
G\u00f6zde de, g\u00f6r\u00fcnt\u00fcy\u00fc olu\u015fturan bir d\u0131\u015fb\u00fckey mercek sistemi vard\u0131r. \u00d6ndeki kavisli, saydam katman (kornea) ile aras\u0131ndaki suyumsu s\u0131v\u0131 bir s\u0131v\u0131 mercek olu\u015fturur; g\u00f6zbebe\u011finden (iristeki k\u00fc\u00e7\u00fck delik ) g\u00f6ze giren \u0131\u015f\u0131k, ilk a\u015famada bu mercek taraf\u0131ndan odaklan\u0131r. Sonra \u0131\u015f\u0131k, g\u00f6zbebe\u011finin ard\u0131nda yer alan, i\u00e7teki d\u0131\u015fb\u00fckey g\u00f6z merce\u011finden ge\u00e7er. Bak\u0131lmakta olan cismin g\u00f6r\u00fcnt\u00fcs\u00fcn\u00fcn odaklama ayar\u0131n\u0131n yap\u0131labilmesi i\u00e7in, k\u00fc\u00e7\u00fck kaslar g\u00f6z merce\u011finin e\u011frili\u011fini ve bi\u00e7imini de\u011fi\u015ftirebilir. G\u00f6r\u00fcnt\u00fc, g\u00f6z\u00fcn arkas\u0131nda, a\u011ftabaka denen \u0131\u015f\u0131\u011fa duyarl\u0131 bir alan\u0131n \u00fczerinde olu\u015fur. Mercek sistemi d\u0131\u015fb\u00fckey oldu\u011fundan g\u00f6r\u00fcnt\u00fc ba\u015f a\u015fa\u011f\u0131 gelmi\u015f durumdad\u0131r;g\u00f6r\u00fcnt\u00fcy\u00fc do\u011fru konuma getiren beyindir.<\/p>\n
Merce\u011fin Olu\u015fturdu\u011fu G\u00f6r\u00fcnt\u00fc:
\n Elinize d\u0131\u015fb\u00fckey, yani yak\u0131nsak bir mercek al\u0131n ve merce\u011fi bir cisme iyice yakla\u015ft\u0131r\u0131n; \u00f6yle ki, mercek ile cisim aras\u0131ndaki uzakl\u0131k, merce\u011fin odak uzakl\u0131\u011f\u0131ndan daha k\u00fc\u00e7\u00fck olsun. Bu durumda cismi do\u011fal konumunda, am b\u00fcy\u00fclt\u00fclm\u00fc\u015f olarak g\u00f6receksiniz. Daha sonra merce\u011fin ard\u0131na, yani sizin bakt\u0131\u011f\u0131n\u0131z taraf\u0131na bir kart koyun; bu durumda, kart\u0131n \u00fczerinde cismin g\u00f6r\u00fcnt\u00fcs\u00fcn\u00fcn olu\u015fmad\u0131\u011f\u0131n\u0131 fark edeceksiniz(oysa pencereye tutulan mercek \u00f6rne\u011finde g\u00f6r\u00fcnt\u00fc olu\u015fmu\u015ftu ). Kart, film yada ekran \u00fczerine d\u00fc\u015f\u00fcr\u00fclebilen g\u00f6r\u00fcnt\u00fclere \u201cger\u00e7ek \u201c g\u00f6r\u00fcnt\u00fc denir. Bu t\u00fcr y\u00fczeylerin \u00fczerinde olu\u015fturulamayan g\u00f6r\u00fcnt\u00fclere de sanal g\u00f6r\u00fcnt\u00fc ad\u0131 verilir yada eski ad\u0131yla zahiri g\u00f6r\u00fcnt\u00fc denir. Sanal g\u00f6r\u00fcnt\u00fcler ancak merce\u011fin i\u00e7inden bak\u0131larak g\u00f6r\u00fclebilir.
\n Bir b\u00fcy\u00fcte\u00e7 ya da oyuncak bir teleskopla bakarken, g\u00f6zlenen cismin \u00e7evresinde genellikle renkli sa\u00e7aklar\u0131n olu\u015ftu\u011funu g\u00f6r\u00fcrs\u00fcn\u00fcz. Bunun nedeni farkl\u0131 renklerden \u0131\u015f\u0131k \u0131\u015f\u0131nlar\u0131n\u0131n mercekten ge\u00e7erken farkl\u0131 a\u00e7\u0131larla k\u0131r\u0131lmas\u0131d\u0131r. \u00d6rne\u011fin, mavi \u0131\u015f\u0131k \u0131\u015f\u0131nlar\u0131 k\u0131rm\u0131z\u0131 \u0131\u015f\u0131k \u0131\u015f\u0131nlar\u0131ndan daha b\u00fcy\u00fck bir a\u00e7\u0131yla k\u0131r\u0131lmaya u\u011frar. Beyaz \u0131\u015f\u0131k, g\u00f6kku\u015fa\u011f\u0131ndaki b\u00fct\u00fcn renklerin kar\u0131\u015f\u0131m\u0131ndan olu\u015ftu\u011fu i\u00e7in, g\u00f6r\u00fcnt\u00fcn\u00fcn \u00e7evresinde bir g\u00f6kku\u015fa\u011f\u0131 sa\u00e7a\u011f\u0131 olu\u015fur. Bu sa\u00e7a\u011f\u0131 gidermek i\u00e7in mercek, her biri ayr\u0131 t\u00fcr camdan yap\u0131lm\u0131\u015f iki katman halinde haz\u0131rlan\u0131r. Bu tip merceklere bile\u015fik mercek denir. Bunlar\u0131n \u00fcretimi olduk\u00e7a zor ve masrafl\u0131d\u0131r; kaliteli foto\u011fraf makinelerinin ve d\u00fcrb\u00fcnlerin pahal\u0131 olmas\u0131n\u0131n nedeni de budur.
\n Merceklerin Yap\u0131m\u0131 ve Tarihi:
\n Mercekler, cam bloklar\u0131n\u0131n karborundum (silisyum karb\u00fcr) ya da korindon (al\u00fcminyum oksit) gibi a\u015f\u0131nd\u0131r\u0131c\u0131 bir tozla z\u0131mparalanmas\u0131ndan sonra, demir oksitli bir cila macunuyla perdahlanmas\u0131(parlat\u0131lmas\u0131) yoluyla haz\u0131rlan\u0131r. Bu i\u015flemlerden baz\u0131lar\u0131 makineyle ger\u00e7ekle\u015ftirilir, ama gene de mercek yap\u0131ms\u00fcreci yava\u015f ve pahal\u0131d\u0131r; son perdah i\u015flemi ve merce\u011fin s\u0131nanmas\u0131 b\u00fcy\u00fck h\u00fcner ister. G\u00fcn\u00fcm\u00fczde, g\u00f6zl\u00fck cam\u0131, kontak lens ve b\u00fcy\u00fcte\u00e7 yap\u0131m\u0131nda plastiklerden de yararlan\u0131l\u0131r; bu t\u00fcr g\u00f6zl\u00fck camlar\u0131na piyasada organik cam denir.
\n Eski Yunanl\u0131lar ve Romal\u0131lar, g\u00fcne\u015f \u0131\u015f\u0131nlar\u0131n\u0131 odakl\u0131yarak ate\u015f yakmak i\u00e7in bazen i\u00e7i su dolu cam kaplardan yararlan\u0131rlard\u0131. G\u00f6zl\u00fck ve b\u00fcy\u00fcte\u00e7 1300\u2019den \u00f6nce; teleskop 1608\u2019de icat edildi. \u00c7ok g\u00fc\u00e7l\u00fc bir b\u00fcy\u00fcte\u00e7 t\u00fcr\u00fc olan M\u0130KROSKOP;TELESKOP kendi maddelerinde ayr\u0131nt\u0131l\u0131 olarak i\u015flenmi\u015ftir. Toplui\u011fne ba\u015f\u0131 b\u00fcy\u00fckl\u00fc\u011f\u00fcndeki merceklerden, 1 metre \u00e7ap\u0131ndaki merceklere kadar \u00e7ok de\u011fi\u015fik boyutlarada mercekler yap\u0131labilir. ABD\u2019de, Wisconsin\u2019deki Yerkes G\u00f6zlemevi\u2019nde bulunan b\u00fcy\u00fck teleskopun objektif b\u00fcy\u00fckl\u00fc\u011f\u00fc 1 metredir.<\/p>\n","protected":false},"excerpt":{"rendered":"
Ayna, insan\u0131n kendisini g\u00f6rmesi i\u00e7in kulland\u0131\u011f\u0131 cam veya maden levhad\u0131r. Mercek ise i\u00e7inden ge\u00e7en paralel \u0131\u015f\u0131nlar\u0131 birbirine yakla\u015ft\u0131ran ya da uzakla\u015ft\u0131ran saydam bir cisimdir. \u0130nsan g\u00f6z\u00fcn\u00fcn g\u00f6rmesini g\u00f6z merce\u011fi sa\u011flar. G\u00f6rme bozuklu\u011funu gidermek i\u00e7in merceklerden olu\u015fan g\u00f6zl\u00fck tak\u0131l\u0131r. Foto\u011fraf makinesi ve b\u00fcy\u00fcte\u00e7 de, mercekle \u00e7al\u0131\u015fan ara\u00e7lard\u0131r. Mikrokskop, teleskop ve di\u011fer bir\u00e7ok \u00f6l\u00e7me ara\u00e7lar\u0131nda mercekler ve …<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1407,1403],"tags":[7063,3311,2737,6983,2742,7061,2734,2736,2740,7062,2728],"class_list":["post-2930","post","type-post","status-publish","format-standard","hentry","category-fen-ve-teknoloji-odevleri","category-odevler","tag-disbukey-mercekler","tag-elektrostatik-mercek","tag-geometri","tag-kondansator","tag-mercek-cesitleri","tag-mercek-sapinclari","tag-mercekler-ve-aynalar","tag-mikrokskop","tag-optik","tag-ozel-mercekler","tag-teleskop"],"_links":{"self":[{"href":"https:\/\/www.islamidavet.com\/kutuphane\/wp-json\/wp\/v2\/posts\/2930","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.islamidavet.com\/kutuphane\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.islamidavet.com\/kutuphane\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.islamidavet.com\/kutuphane\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.islamidavet.com\/kutuphane\/wp-json\/wp\/v2\/comments?post=2930"}],"version-history":[{"count":0,"href":"https:\/\/www.islamidavet.com\/kutuphane\/wp-json\/wp\/v2\/posts\/2930\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.islamidavet.com\/kutuphane\/wp-json\/wp\/v2\/media?parent=2930"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.islamidavet.com\/kutuphane\/wp-json\/wp\/v2\/categories?post=2930"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.islamidavet.com\/kutuphane\/wp-json\/wp\/v2\/tags?post=2930"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}